Week 4 Quiz - MCQGeeks.com

sources of genetic variation

0%
Populations may grow faster than their resources.
0%
Mutations, recombination, independent assortment , you don't know which gamete will succeed
0%
Sampling from generation to generation is more variable in small populations than large.
0%
Individuals can migrate in and out of a population, as long as the population size remains constant.

sexual selection

0%
A change in the frequency of an allele due to the random effects of limited population size is called genetic drift.In each generation, some individuals may, just by chance, leave behind a few more descendents (and genes, of course!) than other individuals. The genes of the next generation will be the genes of the "lucky" individuals, not necessarily the healthier or "better" individuals. That, in a nutshell, is genetic drift
0%
behavior by individuals that may decrease their chance of survival but increases that of their kin (who share a proportion of their genes) ie: give up having kids because your really related to your sistersHaplo-diploid systems have sisters that are more related to each other than they are to their mother! There are other organisms known for altruistic behavior that don't have the haplo-diploid system Reciprocal altruism- I'll do something nice for you now, and you'll do something for me later
0%
Male trait & female preference passed down both maternal & paternal linesFor sexual dimorphism to work out, you have got to have the allele in both genders- both need to have it because they only give 1 allele each to their kidwhen you introduce predators to the mix, the showiness of the trait goes down because you have interplay between sexual selection and natural selection
0%
mating pattern and a form of sexual selection in which individuals with similar phenotypes mate with one another more frequently than would be expected under a random mating pattern

For reciprocal altruism to work, individuals must be able to: calculate the fitness value of individual interactions. recognize one another. remember previous interactions. recognize one another, remember previous interactions, and calculate the fitness value of individual interactions. recognize one another and remember previous interactions.

0%
There is more variety in the gene pool of snails than humans.
0%
when males and females looks different (ex: humans)distinct difference in size or appearance between the sexes of an animal in addition to difference between the sexual organs themselves
0%
migration, mutation, genetic drift, and non-random mating.
0%
recognize one another and remember previous interactions.

Which mode(s) of selection will not necessarily change the mean trait value in a population?

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stabilizing
0%
substantial differences between their genetic sequences.
0%
StabilizingDisruptive
0%
the frequency of heterozygotes

There are other mechanisms that can cause allele and genotype frequencies to change. These are :

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The mutation may be expressed in the individual, but will not be passed along to its offspring.
0%
genetic drift
0%
There is more variety in the gene pool of snails than humans.
0%
migration, mutation, genetic drift, and non-random mating.

Hardy Weinberg principle shows that evolution is not happening

0%
Genotypes: AA Aa aagenotype frequencies: p^2 + 2pq + q^2 = 1Genotypic frequency shifts with your allele frequency
0%
Sampling from generation to generation is more variable in small populations than large.
0%
1. There can be no differences in the survival and reproductive success of individuals. 2. Populations must not be added to or subtracted from by migration. 3. There can be no mutation. 4. The population must be sufficiently large to prevent sampling errors. 5. Individuals must mate at random.
0%
evolution has occurred because one or more of the assumptions of the Hardy-Weinberg equilibrium has been violated.

3 modes of selection

0%
Populations may grow faster than their resources.
0%
Mutations, recombination, independent assortment , you don't know which gamete will succeed
0%
something that sterilizes or kills you
0%
1. directional2. stabilizing3. disruptive

Hardy Weinberg Equilibrium

0%
1. There can be no differences in the survival and reproductive success of individuals. 2. Populations must not be added to or subtracted from by migration. 3. There can be no mutation. 4. The population must be sufficiently large to prevent sampling errors. 5. Individuals must mate at random.
0%
how many offspring you leave in the next generationDirect fitness: # of kids you have X relatedness (1/2) (if your diploid and give half your genes to next generation)3 kids (1/2) = 1.5Indirect fitness: siblings X relatedness + siblings kids X relatednessInclusive fitness= direct + indirect fitness
0%
Microevolution: Change in allele OR genotype frequencies in a population over one or more generationsMacroevolution:Basically the same thing, except over a period of time long enough to allow for substantial phenotypic change
0%
Male trait & female preference passed down both maternal & paternal linesFor sexual dimorphism to work out, you have got to have the allele in both genders- both need to have it because they only give 1 allele each to their kidwhen you introduce predators to the mix, the showiness of the trait goes down because you have interplay between sexual selection and natural selection

Kin selection

0%
behavior by individuals that may decrease their chance of survival but increases that of their kin (who share a proportion of their genes) ie: give up having kids because your really related to your sistersHaplo-diploid systems have sisters that are more related to each other than they are to their mother! There are other organisms known for altruistic behavior that don't have the haplo-diploid system Reciprocal altruism- I'll do something nice for you now, and you'll do something for me later
0%
mating pattern and a form of sexual selection in which individuals with similar phenotypes mate with one another more frequently than would be expected under a random mating pattern
0%
Male trait & female preference passed down both maternal & paternal linesFor sexual dimorphism to work out, you have got to have the allele in both genders- both need to have it because they only give 1 allele each to their kidwhen you introduce predators to the mix, the showiness of the trait goes down because you have interplay between sexual selection and natural selection
0%
how many offspring you leave in the next generationDirect fitness: # of kids you have X relatedness (1/2) (if your diploid and give half your genes to next generation)3 kids (1/2) = 1.5Indirect fitness: siblings X relatedness + siblings kids X relatednessInclusive fitness= direct + indirect fitness

Why can't we measure genetic variation in a population using observable traits (phenotypes)? (Select all that apply.) The environment can also affect the phenotype. Many traits are encoded by multiple genes. All traits are encoded by a single gene. Phenotypes are not determined by genes.

0%
1.Environmental change:2. Developmental constraints and/or selective trade-offs:- a given trait will eventually reach a point where it can't get any bigger or smaller
0%
The mutation may be expressed in the individual, but will not be passed along to its offspring.
0%
The environment can also affect the phenotype. Many traits are encoded by multiple genes.
0%
the degree of genetic relatedness of this meerkat to all members of the group

how do we know if a population is evolving?

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1. There can be no differences in the survival and reproductive success of individuals. 2. Populations must not be added to or subtracted from by migration. 3. There can be no mutation. 4. The population must be sufficiently large to prevent sampling errors. 5. Individuals must mate at random.
0%
Most mutations are deleterious and produce an extreme phenotype that is selected against.
0%
Microevolution: Change in allele OR genotype frequencies in a population over one or more generationsMacroevolution:Basically the same thing, except over a period of time long enough to allow for substantial phenotypic change
0%
evolution has occurred because one or more of the assumptions of the Hardy-Weinberg equilibrium has been violated.

Assortative Mating

0%
Microevolution: Change in allele OR genotype frequencies in a population over one or more generationsMacroevolution:Basically the same thing, except over a period of time long enough to allow for substantial phenotypic change
0%
Mutations, recombination, independent assortment , you don't know which gamete will succeed
0%
Male trait & female preference passed down both maternal & paternal linesFor sexual dimorphism to work out, you have got to have the allele in both genders- both need to have it because they only give 1 allele each to their kidwhen you introduce predators to the mix, the showiness of the trait goes down because you have interplay between sexual selection and natural selection
0%
mating pattern and a form of sexual selection in which individuals with similar phenotypes mate with one another more frequently than would be expected under a random mating pattern

fitness

0%
Male trait & female preference passed down both maternal & paternal linesFor sexual dimorphism to work out, you have got to have the allele in both genders- both need to have it because they only give 1 allele each to their kidwhen you introduce predators to the mix, the showiness of the trait goes down because you have interplay between sexual selection and natural selection
0%
A change in the frequency of an allele due to the random effects of limited population size is called genetic drift.In each generation, some individuals may, just by chance, leave behind a few more descendents (and genes, of course!) than other individuals. The genes of the next generation will be the genes of the "lucky" individuals, not necessarily the healthier or "better" individuals. That, in a nutshell, is genetic drift
0%
how many offspring you leave in the next generationDirect fitness: # of kids you have X relatedness (1/2) (if your diploid and give half your genes to next generation)3 kids (1/2) = 1.5Indirect fitness: siblings X relatedness + siblings kids X relatednessInclusive fitness= direct + indirect fitness
0%
1. There can be no differences in the survival and reproductive success of individuals. 2. Populations must not be added to or subtracted from by migration. 3. There can be no mutation. 4. The population must be sufficiently large to prevent sampling errors. 5. Individuals must mate at random.

If two populations are thought to be diverging from one another, what would you expect to observe? an increase in similarity of alleles coding for proteins the same genotypes, but different phenotypes an accumulation of different mutations in different populations more shared mutations in different populations

0%
evolution has occurred because one or more of the assumptions of the Hardy-Weinberg equilibrium has been violated.
0%
an accumulation of different mutations in different population
0%
substantial differences between their genetic sequences.
0%
There is more variety in the gene pool of snails than humans.

selective agent

0%
1. directional2. stabilizing3. disruptive
0%
something that sterilizes or kills you
0%
No, because there is nonrandom mating.
0%
mating pattern and a form of sexual selection in which individuals with similar phenotypes mate with one another more frequently than would be expected under a random mating pattern

genetic driftDrift tends to reduce genetic variation - the extent to which it does this is dependent upon population size (drift has a stronger effect on smaller populations), not on the existing amount of variation.

0%
A change in the frequency of an allele due to the random effects of limited population size is called genetic drift.In each generation, some individuals may, just by chance, leave behind a few more descendents (and genes, of course!) than other individuals. The genes of the next generation will be the genes of the "lucky" individuals, not necessarily the healthier or "better" individuals. That, in a nutshell, is genetic drift
0%
Populations may grow faster than their resources.
0%
gene flow
0%
No, because there is nonrandom mating.

A crate of grapes lifted 10 meters gains 200 J of potential energy. If the same crate is instead lifted 20 meters, its gain in potential energy is _________.

0%
twice as much
0%
90 cm (10 cm from the weight)
0%
the left truck
0%
the same

When a rock tied to a string whirled in a horizontal circle somehow doubles in mass but keeps the same speed, the string tension _________.

0%
doubles
0%
increases
0%
v= √2gh
0%
slows

Two people are balanced on a seesaw. If one person leans inward toward the center of the seesaw, that person's end of the seesaw tends to _________.

0%
90 m
0%
100%
0%
slows
0%
rise

Suppose we replace the mass in the video with one that is four times heavier. How far from the free end must we place the pivot to keep the meter stick in balance?

0%
90 cm (10 cm from the weight)
0%
the easiest is choked up and a short bat
0%
ω= 3.00 rotations per second
0%
no, it takes energy to make hydrogen

In the hydraulic machine shown, you observe that when the small piston is pushed down 10 cm, the large piston is raised 1 cm.If the small piston is pushed down with a force of 100 N, what is the most weight that the large piston can support?

0%
d, a&b, c, e
0%
W= 1,000 N
0%
10 N
0%
20 N

Distinguish between linear momentum and angular momentum.

0%
angular momentum depends on the distribution of mass, whereas linear momentum depends on the total mass
0%
(rotation, leverage, distance from an axis of rotation)all the above
0%
the center of mass and the center of gravity are both at the center of the spherical ball
0%
most of the mass is concentrated far from the axis

A) Calculate the work done in lifting a 460-N barbell 1.6 m above the floor.B) What is the gain of the potential energy of the barbell when it is lifted to this height?

0%
remains the same, but the revolutions per minute decrease
0%
A) W= 740 JB) ΔU = 740 J
0%
A) b, a, cB) cC) it quadrupledD) the solid sphere
0%
four times the kinetic energy

Calculate the tension in a horizontal string that whirls a 2.2-kg toy in a circle of radius 2.0 m when it moves at 2.6 m/s on an icy surface.centripetal force: F= mv^2/r

0%
h= 0.12 m
0%
A) T= 21 N*mB) F= 210 NC) yes
0%
F= 170 N
0%
F= 7.4 N

The work that is done when twice the load is lifted twice the distance is _________.

0%
in the center of the ball
0%
the same as its potential energy
0%
by a factor of four
0%
four times as much

How can gravity be simulated in an orbiting space station?

0%
it is the perpendicular distance from the rotational axis to the line along which the force acts
0%
(spin a station shaped like a bicycle wheel, spin two pods connected by a cable, rotate a cylinder to create centrifugal force as viewed by a person on the inside of the curved outer wall)all of the above
0%
(he has gained an amount of kinetic energy equal to half his initial potential energy, his potential energy is halved, his kinetic energy and potential energy are equal)all of the above
0%
rotation

On a rotating turntable, how do tangential speed and rotational speed vary with distance from the center?

0%
a vertical line through the center of gravity passes inside its support base
0%
it takes four times the work and four times the stopping distance
0%
(a radial distance, two types of speed)both of these
0%
tangential speed increases with distance; rotational speed is constant

The work you do when pushing a shopping cart twice as far while applying the same force is _________.

0%
increases
0%
a support force
0%
the same
0%
twice as much

Calculate the kinetic energy of an 86-kg scooter moving at 12 m/s.

0%
KE=6200 J
0%
A) W= 740 JB) ΔU = 740 J
0%
wide handle
0%
destroyed

Which will have the greater acceleration rolling down an incline: a hoop or a solid disk? Why?

0%
somewhere straight below where your hands grab the rope
0%
the solid disk will because the mass is closer to the axis of rotation
0%
the radial component of the normal force
0%
a vertical line through the center of gravity must pass inside the support base of the object

Why does bending your legs when running enable you to swing your legs to and fro more rapidly?

0%
bending your legs shortens them, thus reducing rotational inertia
0%
the car with twice the mass has twice the gain of potential energy
0%
it is not a fundamental force of natureinstead, it is a force that only appears in an accelerating frame of reference
0%
it has four times as much

The bob of a simple pendulum has its maximum kinetic energy at the _________.

0%
both take the same 1000 J
0%
by a factor of four
0%
bottom of its swing
0%
halfway down

A motorcycle moving at 50 km/h skids 10 m with locked brakes. How far will it skid with locked brakes when traveling at 150 km/h?

0%
zero
0%
90 m
0%
T= 9.1 Nm
0%
the same

After rolling halfway down an incline, a marble's kinetic energy is _________.

0%
the same as its potential energy
0%
it has four times as much
0%
when the potential energy changes
0%
increased mass and increased distance to mass concentration

What is the source of energy in sunshine?

0%
thermonuclear fusion energy
0%
curled into a ball shape
0%
m/s for tangential, RPM for rotational
0%
the Sun

Where is the center of mass of a baseball? Where is its center of gravity?

0%
the same as its potential energy
0%
the center of mass and the center of gravity are both at the center of the spherical ball
0%
nuclear power in Earth's interior
0%
m/s for tangential, RPM for rotational

A force sets an object in motion. When the force is multiplied by the time of its application, we call the quantity impulse, and an impulse changes the momentum of that object. What do we call the quantity force multiplied by distance?

0%
two
0%
work
0%
v= √2gh
0%
50%

Two identical golf carts move at different speeds. The faster cart has twice the speed and therefore has _________.

0%
A) the mouthB) vm/vb= 1.3
0%
the left truck
0%
four times the kinetic energy
0%
axis along the head, through the center, through one end

If you balance a broom horizontally on one finger, the center of gravity of the broom will be above your finger, closer to the bristles end than the handle end. If you saw the broom in two pieces at that point and weigh the two pars on a scale, you'll find that the heavier part is the _________.

0%
somewhere straight below where your hands grab the rope
0%
there is no force as viewed by someone outside the carto them you move in a straight line
0%
bristles part
0%
rotates faster

As a huge rotating cloud of particles in space gravitate together forming an increasingly dense ball, it shrinks in size and _________.

0%
it increases
0%
rotates faster
0%
twice as much
0%
four times

Exactly what is it that enables an object to do work?

0%
four times as much
0%
when the potential energy changes
0%
energy
0%
the same

Calculate the torque produced by a 48-N perpendicular force at the end of a 0.19-m long wrench.torque=lever arm x force

0%
m= 1.3 kg
0%
T= 9.1 Nm
0%
10 kJ
0%
h= 0.12 m

Recycled energy is mainly _________.

0%
90 cm (10 cm from the weight)
0%
energy
0%
curled into a ball shape
0%
use of energy otherwise wasted

Consider three axes of rotation for a pencil: along the lead, at right angles to the lead at the middle, and at right angles to the lead at one end. Rate the rotational inertias about each axis from smallest to largest.

0%
it takes four times the work and four times the stopping distance
0%
the force is inward on clothes and there is none on water
0%
axis along the head, through the center, through one end
0%
A) it decreasesB) it decreasesC) it decreases

How is a flywheel constructed to maximize its rotational inertia?

0%
PE=mgh=(3.0 kg) (10 m/s^2) (1/2 m) = 36 J
0%
it would have twice as much potential energy
0%
(a radial distance, two types of speed)both of these
0%
most of the mass is concentrated far from the axis

A force of 50 N is applies to the end of a lever, which is moved a certain distance. If the other end of the lever moves one-third as far, how much force does it exert?

0%
W=Fd=(8.0 N) (1.2 m) = 9.6 J
0%
10 kJ
0%
100 J
0%
150 N

An apple hanging from a limb has potential energy because of its height. If it falls, what becomes of this energy just before it hits the ground? When it hits the ground?

0%
it takes four times the work and four times the stopping distance
0%
immediately before hitting the ground the apple's energy is kinetic energy; when it hits the ground, its energy becomes thermal energy
0%
tangential speed increases with distance; rotational speed is constant
0%
(he has gained an amount of kinetic energy equal to half his initial potential energy, his potential energy is halved, his kinetic energy and potential energy are equal)all of the above

Nellie Newton applies a force of 58 N to the end of a lever, which is moved a certain distance. If the other end of the lever moves one-third as far, find the force it exerts.

0%
F= 7.4 N
0%
A) T= 21 N*mB) F= 210 NC) yes
0%
F= 170 N
0%
300 J

How does speed affect the friction between a road and a skidding tire?

0%
force and leverage distance
0%
no, it takes energy to make hydrogen
0%
quadruples the tension in the string
0%
speed has no effect on the friction

If you hang at rest by your hands from a long vertical rope, where is your center of gravity with respect to the rope?

0%
somewhere straight below where your hands grab the rope
0%
quadruples the tension in the string
0%
PE=mgh=(1000 kg) (10 N/kg) (3 m) = 30,000 J
0%
(momentum, potential energies, inertias, kinetic energies)none of the above

A machine puts out 100 watts of power for every 1,000 watts put into it. The efficiency of the machine is _________.

0%
100%
0%
10%
0%
zero
0%
distance is diminished to one-quarter

A light aluminum ball and a heavy lead ball of the same size roll down an incline. When they are halfway down the incline, they will have identical _________.

0%
(momentum, potential energies, inertias, kinetic energies)none of the above
0%
increased mass and increased distance to mass concentration
0%
the tangential speed of the wide end is faster
0%
(rotation, leverage, distance from an axis of rotation)all the above

A) Is it easier to balance a long rod with a mass attached to it when the mass is closer to your hand or when the mass is further away?B) How does the rotational inertia of the rod with the mass toward the bottom compare with the rotational inertia of the mass toward the top?C) Why does the rotational inertia of the rod with the attached mass closer to your hand compare the way it does with the rotational inertia of the the rod with the attached mass further away?D) Is it easier for a circus performer to balance a long rod held vertically with people hanging off the other end, or the same long rod without the people at the other end, and why?

0%
the force is inward on clothes and there is none on water
0%
no, it takes energy to make hydrogen
0%
there is no force as viewed by someone outside the carto them you move in a straight line
0%
A) it is easier when the mass is farther from your handB) the rotational inertia of the rod with the mass closer to the top is greater than the rotational inertia of the rod with the mass closer to the bottomC) rotational inertia depends on whether the mass is farther or closer to the point of rotation. the farther the mass is, the higher the rotational inertiaD) it is easier for the performer to balance a long rod held vertically with people at the other end because the rotational inertia is greater

What is the law of inertia for rotating systems in terms of angular momentum?

0%
angular momentum does not change without an applied external torque
0%
a vertical line through the center of gravity must pass inside the support base of the object
0%
50 J
0%
rotating

A ball rolling down an incline has its maximum kinetic energy at _________.

0%
KE=6200 J
0%
the bottom
0%
T= 9.1 Nm
0%
rotates faster

Consider an ideal pulley system.If you pull one end of the rope 0.60 m downward with a 46-N force, find the height you can lift a 230-N load.

0%
h= 0.12 m
0%
T= 9.1 Nm
0%
twice as much
0%
wide handle

When is the potential energy of something significant?

0%
force and leverage distance
0%
quadruples the tension in the string
0%
the center of mass and the center of gravity are both at the center of the spherical ball
0%
when the potential energy changes

Multiply the equation for linear momentum by radial distance r and you have _________.

0%
four times as much
0%
m/s for tangential, RPM for rotational
0%
twice as much
0%
angular momentum

What does a torque tend to do to an object?

0%
300 J
0%
increased mass and increased distance to mass concentration
0%
the car with twice the mass has twice the gain of potential energy
0%
torque tends to twist or change the state of rotation of the object

Which energy production method does not ultimately depend on the Sun?

0%
halfway down
0%
curled into a ball shape
0%
nuclear fission
0%
angular momentum

A) How does the lever arm change if you decrease the angle of the force?B) How does the lever arm change when you decrease the distance to the nut?C) How does the force needed to turn the wrench change if you increases the lever arm?

0%
A) it decreasesB) it decreasesC) it decreases
0%
A) the mouthB) vm/vb= 1.3
0%
the tangential speed is proportional to the radiusthe inside of the wheel rolls on a larger radius than the outside of the wheel
0%
it will rotate about the center of mass

Suppose our experimenter repeats his experiment on a planet more massive than Earth, where the acceleration due to gravity is g= 30 m/s^When he releases the ball from chin height without giving it a push, how will the ball's behavior differ from its behavior on Earth? Ignore friction and air resistance.

0%
it will take less time to return to the point from which it was released
0%
50%
0%
bending your legs shortens them, thus reducing rotational inertia
0%
50 J

Fossil fuels, hydroelectric power, and wind power ultimately get their energy from _________.

0%
the top
0%
the Sun
0%
increases
0%
doubles

What is required to change the angular momentum of a system?

0%
angular momentum
0%
increases
0%
nuclear fission
0%
external torque

A) How much work is done when you push a crate horizontally with 150 N across a 15-m factory floor?B) If the force of friction on the crate is a steady 70 N, find the KE gained by the crate.C) Find the energy turned into heat.

0%
PE=mgh=(1000 kg) (10 N/kg) (3 m) = 30,000 J
0%
A) W=2300 JB) K=1200 JC) Q=1050 J
0%
90 cm (10 cm from the weight)
0%
P=W/t=(100 J)/(4 s)= 25 W

Belly-flop Bernie dives from atop a a tall flagpole into a swimming pool below. His potential energy at the top is 12,000 J (relative to the surface of the pool).What is his kinetic energy when his potential energy reduces to 1,000 J?

0%
a support force
0%
T= 30 N*m
0%
KE= 1.1x10^4 J
0%
90 cm (10 cm from the weight)

The diameter of the base of a tapered drinking cup is 6.8 cm. The diameter of its mouth is 8.6 cm. The path of the cup curves when you roll it on the top of a table.A) Which end, the base or the mouth, rolls faster?B) How much faster?

0%
A) the mouthB) vm/vb= 1.3
0%
ω= 3.00 rotations per second
0%
Art has half the mass of Bart
0%
both take the same 1000 J

A 2-kg box of taffy candy has 40 J of potential energy relative to the ground. Its height above the ground is _________.

0%
T= 9.1 Nm
0%
60%
0%
10%
0%
2 m

If you push a crate horizontally with 100 N across a 10-m factory floor and the friction between the crate and the floor is a steady 70 N, how much kinetic energy does the crate gain?

0%
100 J
0%
b, c, a
0%
60%
0%
300 J

If a machine multiplies force by a factor of 4, what other quantity is diminished, and by how much?

0%
distance is diminished to one-quarter
0%
the force is inward on clothes and there is none on water
0%
the same as its potential energy
0%
m/s for tangential, RPM for rotational

A torque acting on an object tends to produce _________.

0%
increases
0%
rotation
0%
T= 9.1 Nm
0%
four times

Consider a bob attached by a string, a simple pendulum, that swings to and fro.A) Why doesn't the tension force in the string do work on the pendulum?B) Explain, however, why the force due to gravity on the pendulum at nearly every point does do work on the pendulum.C) What is the single position of the pendulum where "no work by gravity" occurs?

0%
d, a&b, c, e
0%
tangential speed increases with distance; rotational speed is constant
0%
A) tension in the string is everywhere perpendicular to the arc of the pendulum , with no component of tension B) in the case of gravity, a component of gravitational force on the pendulum exists parallel to the arc, which does work and changes the kinetic energy of the pendulumC) at the pendulum's lowest point
0%
the tangential speed of the wide end is faster

Why is centrifugal force in a rotating frame called a "fictitious force"?

0%
it is not a fundamental force of natureinstead, it is a force that only appears in an accelerating frame of reference
0%
the tangential speed is proportional to the radiusthe inside of the wheel rolls on a larger radius than the outside of the wheel
0%
tangential speed increases with distance; rotational speed is constant
0%
it has four times as much

How do clockwise and counterclockwise torques compare when a system is balanced?

0%
1/3 the distance from the fulcrum
0%
they are equal in magnitude and opposite in direction
0%
increased mass and increased distance to mass concentration
0%
the same as its potential energy

A tapered cup rolled on a flat surface makes a circular path. What does this tell you about the tangential speed of the rim of the wide end of the cup compared with that of the rim of the narrow end?

0%
the easiest is choked up and a short bat
0%
the tangential speed of the wide end is faster
0%
the force is inward on clothes and there is none on water
0%
(a radial distance, two types of speed)both of these

In a simple machine, how much work is done when an input of 10 N acts over a distance of 5 m?

0%
40 J
0%
50 J
0%
50%
0%
10 kJ

Compared with a car moving at some original speed, how much work must the brakes of a car supply to stop a car that is moving twice as fast? How will the stopping distances compare?

0%
the force on the ball is at right angles to the ball's motion
0%
the solid disk will because the mass is closer to the axis of rotation
0%
it takes four times the work and four times the stopping distance
0%
it has four times as much

What is the ultimate source of the energy from fossil fuels, dams, and windmills?

0%
thermonuclear fusion energy
0%
the top
0%
the Sun
0%
the center of mass and the center of gravity are both at the center of the spherical ball

The torque exerted by a crowbar on an object increases with increased _________.

0%
force and leverage distance
0%
when the potential energy changes
0%
bottom of its swing
0%
90 cm (10 cm from the weight)

When one does twice the work in twice the time, the power expended is _________.

0%
the same
0%
doubles
0%
increases
0%
wide handle

A difference between linear momentum and angular momentum involves _________.

0%
(a radial distance, two types of speed)both of these
0%
somewhere straight below where your hands grab the rope
0%
they are equal in magnitude and opposite in direction
0%
a vertical line through the center of gravity passes inside its support base

If both sacks in the preceding question are lifted their respective distances in the same time, how does the power required for each compare? How about for the case in which the lighter sack is moved the same distance in half the time?

0%
bristles part
0%
A) the mouthB) vm/vb= 1.3
0%
A) tension in the string is everywhere perpendicular to the arc of the pendulum , with no component of tension B) in the case of gravity, a component of gravitational force on the pendulum exists parallel to the arc, which does work and changes the kinetic energy of the pendulumC) at the pendulum's lowest point
0%
lifted in the same time, the power is the same. the light sack moving in half the time requires double the power

A car is raised a certain distance in a service-station lift, thus giving it potential energy relative to the floor. If it were raised twice as high, how much more potential energy would it have?

0%
it will rotate about the center of mass
0%
it would have twice as much potential energy
0%
A) d, b, c, e, aB) d, b, c, e, aC) a, e, c, b, d
0%
Art has half the mass of Bart

If a skater who is spinning pulls her arms in so as to reduce her rotational inertia by half, how much will her angular momentum change? By how much will her rate of spin change?

0%
A) d, b, c, e, aB) d, b, c, e, aC) a, e, c, b, d
0%
distance is diminished to one-quarter
0%
her angular momentum does not changeher spin rate doubles
0%
(momentum, potential energies, inertias, kinetic energies)none of the above

A ball rolling down an incline has its maximum potential energy at _________.

0%
the top
0%
halfway down
0%
the same
0%
the Sun

A) Where on the track is the skater's kinetic energy the greatest?B) As the skater is skating back and forth, where does the skater have the most potential energy?C) Observe the total energy bar on the Bar Graph. As the skater is skating back and forth, which statement best describes the total energy?D) Match the approximate numerical values on the left with the energy type categories on the right to complete the equations. Assume that the mass of the skater is 75 kg and that the acceleration of gravity is 9.8 N/kg.E) Based on the previous question, which statement is true?F) If the skater started from rest 4 m above the ground (instead of 7m), what would be the kinetic energy at the bottom of the ramp (which is still 1 m above the ground)?G) Consider again the case where the skater starts 7 m above the ground and skates down the track. What is the skater's speed when the skater is at the bottom of the track?H) When the skater starts 7 m above the ground, how does the speed of the skater at the bottom of the track compare to the speed of the skater at the bottom when the skater starts 4 m above the ground?I) If the skater starts from rest at position 1, rank, in increasing order from least to greatest, the kinetic energy of the skater at the five positions shown.

0%
A) the skater's kinetic energy is ... at its maximum value at the lowest point of the trackB) the skater's potential energy is ... at its maximum value at the locations where the skater turns and goes back in the opposite directionC) the total energy is ... the same at all locations of the trackD) total energy at initial position= 5145 Jpotential energy at initial position= 5145 Jkinetic energy at initial position = 0 Jtotal energy at bottom of track = 5145 Jpotential energy at bottom of track= 735 Jkinetic energy at bottom of track = 4410 JE) the kinetic energy at the bottom of the ramp is ... equal to the amount of potential energy loss in going from the initial location to the bottomF) 2205 JG) 11 m/sH) the speed is ... higher, but less than twice as fastI) 1, 3, 5&2, 4
0%
A) in accord with Newton's second law, the component of gravitational force that is parallel to the incline in B produces an acceleration parallel to the inclineB) in accord with the work-energy theorem, that parallel force component multiplied by the distance the ball travels is equal to the change in the ball's kinetic energy
0%
A) the angular acceleration of the pulley is nonzeroB) the cord's tension on the right side of the pulley is higher than on the left side
0%
in the center of the ball

A) A baseball bat can be rotated around many different axes of rotation. Three such possibilities are shown in FigureRank the baseball bat's moment of inertia about each of these three axes of rotation.a: center of batb: end of handlec: length of whole batB) Given the same baseball bat and possible axes of rotation shown in Figure 1, for which axis of rotation would it be the easiest to rotate the bat from rest?C) A girl spins around in a circle trying to make herself dizzy. Without changing her position, she starts spinning twice as fast. By how much did her rotational kinetic energy change?D) A solid sphere and a hollow sphere (spherical shell) of the same mass and same radius rotate with the same amount of kinetic energy. Which one is rotating faster?

0%
A) smoothB) a distance 2h/3 above the floorC) U= -2mgh/3D) ΔU = -mghE) 1/2mv2i+mghi=1/2mv2f+mgF) K increases; U decreases; E stays the sameG) vb = √(v^2)+2ghH) 1/2mv2/i+Wnc=0I) K decreases; U stays the same; E decreasesJ) frictionK) E= 1/2mv^2+mgh
0%
A) b, a, cB) cC) it quadrupledD) the solid sphere
0%
Art has half the mass of Bart
0%
A) positiveB) same for both wheels: tangential speed at the outer edge of the large wheel & tangential speed at the outer edge of the small wheeldifferent for each wheel:time to complete one revolution & angular speedC) the angular speed of the smaller wheel is greater than ωB.D) they take the same amount of timeE) we cannot tell which direction α should be without knowing the direction of the angular velocity ω

If you toss a stick into the air, it appears to wobble all over the place. Specifically, about what place does it wobble?

0%
m/s for tangential, RPM for rotational
0%
it will rotate about the center of mass
0%
the easiest is choked up and a short bat
0%
toward the center of the circle

Can a machine multiply input force? Input distance?Input energy?

0%
distance is diminished to one-quarter
0%
force: yesdistance: yesenergy: no
0%
(a radial distance, two types of speed)both of these
0%
no, it takes energy to make hydrogen

Which requires more work: lifting a 50-kg sack a vertical distance of 2 m or lifting a 25-kg sack a vertical distance of 4 m?

0%
it has four times as much
0%
both take the same 1000 J
0%
the same as its potential energy
0%
bottom of its swing

How does the tapered rim of a wheel on a railroad allow one part of the rim to have a greater tangential speed than another part when it is rolling on a track?

0%
A) it decreasesB) it decreasesC) it decreases
0%
there is no force as viewed by someone outside the carto them you move in a straight line
0%
the tangential speed is proportional to the radiusthe inside of the wheel rolls on a larger radius than the outside of the wheel
0%
the tangential speed of the wide end is faster

A) Two identical cars are driving in opposite directions at the same speed. Their kinetic energies have _____.B) A motorcycle drives up a steeply inclined ramp. The work done on the motorcycle by Earth's gravitational force is _.C) During a certain time interval, the net work done on an object is zero joules. We can be certain that _____.D) The amount of kinetic energy an object has depends on its mass and its speed. Rank the following sets of oranges and cantaloupes from least kinetic energy to greatest kinetic energy.

0%
A) at the balance pointB) the shorter side, where the bristles of the broom are, has a greater weight than the handleC) the torque due to the weight of the shorter side (the bristles of the broom) is equal in magnitude to the torque due to the weight of the longer side, and opposite in direction
0%
A) b, a, cB) cC) it quadrupledD) the solid sphere
0%
A) it decreasesB) it decreasesC) it decreases
0%
A) the same magnitude and signB) negativeC) the object's final speed was the same as its initial speedD) mass: 4m speed: 1/4 v; total mass: 2 m speed: 1/2 v; mass: m speed: v; total mass: 4 m speed: v & mass: 4m speed: v

Why can't you stand with your heels and back to a wall and then bend over to touch your toes and return to your stand-up position?

0%
the car with twice the mass has twice the gain of potential energy
0%
it is not a fundamental force of natureinstead, it is a force that only appears in an accelerating frame of reference
0%
there is no force as viewed by someone outside the carto them you move in a straight line
0%
a vertical line through the center of gravity of your body is in front of the tips of your toes, which is outside your support base

The force responsible for a car moving steadily along a no-friction icy banked curve is due to _________.

0%
the distribution of mass about the axis of rotation
0%
the force on the ball is at right angles to the ball's motion
0%
the car with twice the mass has twice the gain of potential energy
0%
the radial component of the normal force

If Alex wishes to rotate his skateboard, then he must apply a _________.

0%
torque
0%
rotating
0%
the same
0%
the top

Calculate the work done when a 26-N force pushes a cart 4.0 m.

0%
W=100 J
0%
P=W/t=(100 J)/(4 s)= 25 W
0%
T= 30 N*m
0%
100 J

A melon is tossed straight upward with 100 J of kinetic energy. If air resistance is negligible the melon will return to its initial level with a kinetic energy of _________.

0%
1 kg
0%
10%
0%
W=1.8x10^4 J
0%
100 J

No work is done by gravity on a bowling ball that rolls along a bowling alley because _________.

0%
the force on the ball is at right angles to the ball's motion
0%
the same as its potential energy
0%
somewhere straight below where your hands grab the rope
0%
twice as much

Can a force produce a torque when there is no lever arm?

0%
the top
0%
no, it takes energy to make hydrogen
0%
no
0%
energy

Why doesn't the Leaning Tower of Pisa topple over?

0%
a vertical line through the center of gravity passes inside its support base
0%
the solid disk will because the mass is closer to the axis of rotation
0%
it is the perpendicular distance from the rotational axis to the line along which the force acts
0%
bending your legs shortens them, thus reducing rotational inertia

What is recycled energy?

0%
use of energy otherwise wasted
0%
reused energy that otherwise would be wasted
0%
force: yesdistance: yesenergy: no
0%
increased mass and increased distance to mass concentration

Select the correct equations that show that 64 J of work is done when a 8.0-kg block of ice is moved from rest to a speed of 4.0 m/s.

0%
four times the kinetic energy
0%
W=mv^2/2=((8.0 kg) * (4.0 m/s^2)/2= 64 J
0%
it would have twice as much potential energy
0%
the car with twice the mass has twice the gain of potential energy

The rock and meterstick balance at the 25-cm mark, as shown. The meterstick has a mass of 1.3 kg.What must be the mass of the rock?

0%
m= 1.3 kg
0%
b, c, a
0%
twice as much
0%
T= 9.1 Nm

If a trapeze artist rotates once each second while sailing through the air and contracts to reduce her rotational inertia to one-third of what it was, how many rotations per second will result?

0%
has no reaction counterpart
0%
twice as much
0%
ω= 3.00 rotations per second
0%
1/3 the distance from the fulcrum

A small space telescope at the end of a tether line of length L moves at linear speed v about a central space station.A) What will be the linear speed of the telescope if the length of the line is reduced to 0.33 L?B) If the initial linear speed of the telescope is 0.70 m/s, what is its speed when pulled in to one-third its initial distance from the space station?

0%
ω= 3.00 rotations per second
0%
v= √2gh
0%
bristles part
0%
A) vnew= v/0.33B) 2.1 m/s

The work done in pushing a TV set a distance of 2 m with an average force of 20 N is _________.

0%
A) W=2300 JB) K=1200 JC) Q=1050 J
0%
40 J
0%
50 J
0%
100%

Compared with a force, a torque involves _________.

0%
(rotation, leverage, distance from an axis of rotation)all the above
0%
there is no force as viewed by someone outside the carto them you move in a straight line
0%
most of the mass is concentrated far from the axis
0%
m/s for tangential, RPM for rotational

When you do somersaults, you'll more easily rotate when your body is _________.

0%
bottom of its swing
0%
when the potential energy changes
0%
the Sun
0%
curled into a ball shape

Select the correct equation that shows that 25 W of power is required to give a brick 100 J of PE in a time of 4 s.

0%
Efficiency η=(Eout/Ein)⋅100%=((25J)/(100J))⋅100%=25%
0%
P=W/t=(100 J)/(4 s)= 25 W
0%
greater than toward the center
0%
four times the kinetic energy

What is the unit of work?

0%
thermonuclear fusion energy
0%
doubles
0%
reused energy that otherwise would be wasted
0%
joule

In raising a 4,200-N piano with a pulley system, the workers note that for every 2.1 m of rope pulled downward, the piano rises 0.22 m.Ideally, find the force that is required to lift the piano.

0%
b, c, a
0%
A) W= 740 JB) ΔU = 740 J
0%
v= √2gh
0%
F= 440 N

No work is done by gravity on a bowling ball that is resting or moving on a bowling alley because the force of gravity on the ball acts perpendicular to the surface. But on an incline, the force of gravity has a vector component parallel to the alley, as in B.A) How does this component account for the acceleration of the ball?B) How does this component account for the work done on the ball to change its kinetic energy?

0%
A) it is easier when the mass is farther from your handB) the rotational inertia of the rod with the mass closer to the top is greater than the rotational inertia of the rod with the mass closer to the bottomC) rotational inertia depends on whether the mass is farther or closer to the point of rotation. the farther the mass is, the higher the rotational inertiaD) it is easier for the performer to balance a long rod held vertically with people at the other end because the rotational inertia is greater
0%
A) tension in the string is everywhere perpendicular to the arc of the pendulum , with no component of tension B) in the case of gravity, a component of gravitational force on the pendulum exists parallel to the arc, which does work and changes the kinetic energy of the pendulumC) at the pendulum's lowest point
0%
A) in accord with Newton's second law, the component of gravitational force that is parallel to the incline in B produces an acceleration parallel to the inclineB) in accord with the work-energy theorem, that parallel force component multiplied by the distance the ball travels is equal to the change in the ball's kinetic energy
0%
the force on the ball is at right angles to the ball's motion

If the rotational speed of a rotating habitat in space increases, the weight experienced by occupants _________.

0%
increases
0%
wide handle
0%
twice as much
0%
the left truck

The figure below shows two blocks suspended by a single cord over a pulley. The mass of block B is twice the mass of block A, while the mass of the pulley is equal to the mass of block A. The blocks are let free to move and the cord moves on the pulley without slipping or stretching. There is no friction in the pulley axle, and the cord's weight can be ignored.A) Which of the following statements correctly described the system shown in the figure?B) What happens when block B moves downward?

0%
A) positiveB) same for both wheels: tangential speed at the outer edge of the large wheel & tangential speed at the outer edge of the small wheeldifferent for each wheel:time to complete one revolution & angular speedC) the angular speed of the smaller wheel is greater than ωB.D) they take the same amount of timeE) we cannot tell which direction α should be without knowing the direction of the angular velocity ω
0%
A) the mouthB) vm/vb= 1.3
0%
A) the ball returns to Dr. Hewitt, stopping almost exactly at the point where it was releasedB) all of the initial energy of the ball was converted completely back to potential energy when the ball returnedC) the ball leaves Dr. Hewitt and returns to him, going past the point where it was releasedD) the extra energy from the push is converted into kinetic energy, which is then converted into more potential energy at the end of the motion than the ball had when it was released
0%
A) the angular acceleration of the pulley is nonzeroB) the cord's tension on the right side of the pulley is higher than on the left side

Inertia depends on mass; rotational inertia depends on mass and something else. What?

0%
the distribution of mass about the axis of rotation
0%
1/3 the distance from the fulcrum
0%
increased mass and increased distance to mass concentration
0%
they are equal in magnitude and opposite in direction

As distance increases between most of the mass of an object and its center of rotation, how does rotational inertia change?

0%
twice as much
0%
both take the same 1000 J
0%
it increases
0%
four times

A circus diver drops from a high pole into water far below. When he is halfway down _________.

0%
a vertical line through the center of gravity of your body is in front of the tips of your toes, which is outside your support base
0%
the distribution of mass about the axis of rotation
0%
(he has gained an amount of kinetic energy equal to half his initial potential energy, his potential energy is halved, his kinetic energy and potential energy are equal)all of the above
0%
it has four times as much

If the string that holds a whirling can in its circular path breaks, what kind of force causes it to move in a straight-line path: centripetal, centrifugal, or no force? What law of physics supports your answer?

0%
F= 170 N
0%
A) T= 21 N*mB) F= 210 NC) yes
0%
2,000 N
0%
no force; Newton's first law

The second floor of a house is 6 m above the street level. How much work is required to lift a 300-kg refrigerator to the second-story level?

0%
P=W/t=(100 J)/(4 s)= 25 W
0%
PE=mgh=(1000 kg) (10 N/kg) (3 m) = 30,000 J
0%
10 kJ
0%
W=1.8x10^4 J

What is meant by the "lever arm" of a torque?

0%
a vertical line through the center of gravity passes inside its support base
0%
it is the perpendicular distance from the rotational axis to the line along which the force acts
0%
a vertical line through the center of gravity must pass inside the support base of the object
0%
most of the mass is concentrated far from the axis

When the useful energy output of a simple machine is 100 J, and the total energy input is 200 J, the efficiency is _________.

0%
two
0%
50%
0%
four times
0%
90 m

The tangential speed on the outer edge of a rotating carousel is _________.

0%
greater than toward the center
0%
1/3 the distance from the fulcrum
0%
when the potential energy changes
0%
force: yesdistance: yesenergy: no

What is the relationship between the center of gravity and the support base for an object that is in stable equilibrium?

0%
a vertical line through the center of gravity must pass inside the support base of the object
0%
the tangential speed is proportional to the radiusthe inside of the wheel rolls on a larger radius than the outside of the wheel
0%
it is not a fundamental force of natureinstead, it is a force that only appears in an accelerating frame of reference
0%
the solid disk will because the mass is closer to the axis of rotation

Dan and Sue cycle at the same speed. The tires on Dan's bike are larger in diameter than those on Sue's bike. Which wheels, if either, have the greater rotational speed?

0%
W=mv^2/2=((8.0 kg) * (4.0 m/s^2)/2= 64 J
0%
quadruples the tension in the string
0%
Sue's wheels have the greater rotational speed
0%
no, it takes energy to make hydrogen

If you are not wearing a seat belt in a car that rounds a curve, and you slide across your seat and slam against a car door, what kind of force is responsible for your slide: centripetal, centrifugal, or no force?

0%
two
0%
the easiest is choked up and a short bat
0%
it takes four times the work and four times the stopping distance
0%
there is no force as viewed by someone outside the carto them you move in a straight line

To rotate a stubborn screw, it is best to use a screwdriver that has a _________.

0%
increases
0%
KE=6200 J
0%
twice as much
0%
wide handle

The chef at the infamous Fattening Tower of Pizza tosses a spinning disk of uncooked pizza dough into the air. The disk becomes wider during its flight, while its rotational speed _________.

0%
b, c, a
0%
doubles
0%
slows
0%
work

Centrifugal forces are an apparent reality to observers in a reference frame that is _________.

0%
300 J
0%
rotating
0%
four times
0%
heat

As you crawl toward the edge of a large freely-rotating horizontal turntable in a carnival funhouse, the angular momentum of you and the turntable _________.

0%
it will rotate about the center of mass
0%
remains the same, but the revolutions per minute decrease
0%
the car with twice the mass has twice the gain of potential energy
0%
toward the center of the circle