Q.1
A sphere collides with another sphere of identical mass. After collision, the two spheres move. The collision is inelastic. Then the angle between the directions of the two sphere is [ CET 1994]
  • a) 90°
  • b) 0°
  • c) 45°
  • d) different from 90°
Q.2
A smooth sphere of mass M moving with velocity u directly collides elastically with another sphere of mass m at rest. After collision, their final velocities are V and v, respectively. The value of v is [ MPPMT 1995]
  • a)
    ch-5_qn-149choice_img_no1.png
  • b)
    ch-5_qn-149choice_img_no2.png
  • c)
    ch-5_qn-149choice_img_no3.png
  • d)
    ch-5_qn-149choice_img_no4.png
Q.3
The average power required to lift a 100kg mass through a height of 50 metres in approximately 50 seconds would be ( in J/s)
  • a) 50
  • b) 5000
  • c)100
  • d)980
Q.4
A single conservative force F(x) acts on a 2.5 kg particle that moves along the x-axis. The potential energy U(x) is given by U(x)=(10 + (x - 4)2) where x is in meter. At x=6.0m the particle has kinetic energy of 20J. what is the mechanical energy of the system ?
  • a)34 J
  • b)45 J
  • c) 48 J
  • d)49 J
Q.5
How much is the work done in pulling up a block of wood weighing 2KN for a length of 10m on a smooth plane inclined at an angle of 30° with the horizontal ?
  • a) 1.732 KJ
  • b) 17.32 KJ
  • c) 10 KJ
  • d) 100 KJ
Q.6
A force of 7N, making an angle θ with the horizontal, acting on an object displaces it by 0.5m along the horizontal direction. If the object gains K.E. of 2J, what is the horizontal component of the force ?
  • a)2N
  • b) 4 N
  • c)1 N
  • d)14 N
Q.7
A ball of mass 5 kg is sliding on a plane with initial velocity of 10 m/s. If coefficient of friction between surface and ball is 1/2 , then before stopping it will describe...... (g=10 m/s2)
  • a)12.5 m
  • b)5 m
  • c)7.5 m
  • d)10 m
Q.8
The relationship between force and position is shown in the figure given (in one dimensional case) calculate the work done by the force in displacing abody from x=0 cm to x=5 cm
ch-5_que_no-155_img_no1.png
  • a)30 ergs
  • b) 70 ergs
  • c)20 ergs
  • d)60 ergs
Q.9
A ball is released from the top of a tower. what is the ratio of work done by forceof gravity in first, second and third second of the motion of the ball ?
  • a)1 : 2 : 3
  • b) 1 : 4 : 9
  • c) 1 : 3 : 5
  • d)1: 5 : 3
Q.10
A spring of spring constant 103 N/m is stretched initially 4cm from the unstretched position. How much the work required to stretched it further by another 5 cm ?
  • a) 6.5 NM
  • b) 2.5 NM
  • c)3.25 NM
  • d)6.75 NM
Q.11
A 8 kg mass moves along x - axis. Its accelerations as a function of its position is shown in the figure. What is the total work done on the mass by theforce as the mass moves from x=0 tox=6cm ?
ch-5_que_no-159_img_no1.png
  • a) 48 × 10-3 J
  • b) 98 × 10-3 J
  • c)4.8 × 10-3 J
  • d)9.8 × 10-3
Q.12
The work done by a force acting on a body is as shown in the graph. what is the total work done in covering an initial distance of 15m ?
ch-5_que_no-160_img_no1.png
  • a) 50 J
  • b) 75 J
  • c) 100 J
  • d) 25 J
Q.13
A spring gun of spring constant 90 × 102 N/M is compressed 4cm by a ball of mass16g. If the trigger is pulled, calculate the velocity of the ball.
  • a)60 m/s
  • b) 3 m/s
  • c)90 m/s
  • d)30 m/s
Q.14
A uniform chain of length 2m is kept on a table such that a length of 50cm hangs freely from the edge of the table. The total mass of the chain is 5kg. What is the work done in pulling the entire chain on the table. (g=10 m\\s2)
  • a) 7.2 J
  • b)3 J
  • c)4.6 J
  • d)120 J
Q.15
A uniform chain of length L ans mass M is lying on a smooth table and one third of its is hanging vertically down over the edge of the table. If g is acceleration due to gravity, the work required to pull the hanging part on to the table is
  • a)MgL
  • b) MgL / 3
  • c)MgL/9
  • d)MgL / 18
Q.16
A cord is used to lower vertically a block of mass M by a distance d with constantdown-word acceleration g/2 work done by the cord on the block is
  • a) - Mgd/2
  • b) Mgd/4
  • c) -3Mgd/4
  • d) Mgd
Q.17
A block of mass 5 kg is resting on a smooth surface. At what angle a force of 20N be acted on the body so that it will acquired a kinetic energy of 40J after moving 4m
  • a) 30°
  • b) 45°
  • c) 60°
  • d) 120°
Q.18
The potential energy of a body is given by U = A - Bx2 (where x is displacement). The magnitude of force acting on the particle is
  • a)constant
  • b)proportional to x
  • c) proportional to x2
  • d) Inversely proportional to x
Q.19
An open knife edge of mass m is dropped from a height h on a wooden floor. If the blade penetrates upto the depth d into the wood, the average resistance offered by the wood to the knife edge is
  • a) mg
    ch-5_qn-167choice_img_no2.png
  • b)
    ch-5_qn-167choice_img_no3.png
  • c)
    ch-5_qn-167choice_img_no4.png
  • d)
Q.20
A toy car of mass 3.2 kg moves up a ramp under the influence of force F plotted against displacement x. The maximum height attained is given by
ch-5_que_no-168_img_no1.png
  • a) ymax = 5 m
  • b) ymax = 10 m
  • c) ymax = 15 m
  • d) ymax = 20 m
Q.21
A particle of mass 0.5kg travels in a straight line with velocity v=a x3/2 . Where a=5 m-1/2 s-1 The work done by the net force during its displacement from x=0 to x=2m is
  • a)50 J
  • b)45 J
  • c)25 J
  • d)None of these
Q.22
Velocity time graph of a particle of mass 2kg moving in a straight line is as shown in figure. Work done by all forces on the particle is
ch-5_que_no-170_img_no1.png
  • a) 400 J
  • b) -400 J
  • c)-200 J
  • d)200 J
Q.23
A mass of M kg is suspended by a weight-less string, the horizontal force that is required to displace it until the string makes an angle of 60° with the initial vertical direction is
  • a) Mg /√3
  • b) Mg √2
  • c)Mg / √2
  • d)Mg √ 3
Q.24
A spring with spring constant K when stretched through 2cm the potential energyis U. If it is stretched by 6cm. The potential energy will be......
  • a) 6U
  • b) 3U
  • c) 9U
  • d) 18U
Q.25
If linear momentum of body is increased by 1.5%, its kinetic energy increasesby.......%
  • a)0%
  • b)10%
  • c)2.25%
  • d)3%
Q.26
A body having a mass of 0.5 kg slips along the wall of a semi spherical smooth surface of radius 20 cm shown in figure.What is the velocity of body at the bottom of the surface ? (g=10 m/s2)
ch-5_que_no-174_img_no1.png
  • a) √2 m/s
  • b) 2 m/s
  • c)2√2m/s
  • d)4 m/s
Q.27
An engine pump is used to pump a liquid of density ρ continuosly through apipe of cross-sectional area A. If the speed of flow of the liquid in the pipeis v, then the rate at which kinetic energy is being imparted to the liquid is
  • a) ½ A ρ v3
  • b) ½ A ρ v2
  • c) ½ A ρ v
  • d)A ρ v
Q.28
when 2kg mass hangs to a spring of length 50 cm, the spring stretches by 2 cm.The mass is pulled down until the length of the spring becomes 60 cm. What is the amount of elastic energy stored in the spring in this condition, if g=10 m/s2
  • a) 10 J
  • b) 2 J
  • c) 2.5 J
  • d) 5 J
Q.29
Two masses 10kg and 20 kg are connected by a massless spring. A force of 200N acts on 20kg mass. At the instant when the 10 kg mass has an acceleration 12 m/s2 the energy stored in the spring ( k=2400 N/m) will be
ch-5_que_no-177_img_no1.png
  • a)30 J
  • b) √3 J
  • c)3 J
  • d)8 J
Q.30
A block of mass 1 kg is released from rest at t=0 to fall freely under gravity. Power of gravitational force acting on it at t=2s is ( g=10 m/s2)
  • a)200 watt
  • b) 10 watt
  • c)100 watt
  • d)zero
0 h : 0 m : 1 s