Q.1
A cylinder of mass 10kg is sliding on a plane with an initial velocity of 10m/s. If coefficient of friction between surface and cylinder is 0.5, then before stopping it will describe . [Pb. PMT 2001]
  • a) 12.5 m
  • b) 7.5 m
  • c)5 m
  • d)10 m
Q.2
It is easier to draw up a wooden block along an inclined plane than to haul it vertically, principally because . [CPMT 1977; JIPM]
  • a) The friction is reduced
  • b) Only a part of the weight has to be overcome
  • c)The mass becomes smaller
  • d)‘g’ becomes smaller
Q.3
A block of mass M is hanging over a smooth and light pulley through a light string. The other end of the string is pulled by a constant force F. The kinetic energy of the block increases by 20J in 1s. Then
  • a) the tension in the string is Mg
  • b) the tension in the string is F
  • c) the work done by the tension on the block is 20 J in 1s
  • d) the work done by the force of gravity is -20J in 1s
Q.4
The force acting on a particle of mass 1kg, starting from rest from the origin, is shown in the figure. The velocity of the particle at x=2 m is
ch-5_que_no-213_img_no1.png
  • a)2√2 m/s
  • b) √6 m/s
  • c)2 m/s
  • d)√3 m/s
Q.5
A body of mass 5 kg is placed at the origin, and can move only on the x-axis. A force of 10 N is acting on it in a direction making an angle of with the x-axis and displaces it along the x-axis by 4 metres. The work done by the force is . [MP PET 2003]
  • a)2.5 J
  • b) 40 J
  • c)7.25 J
  • d)20 J
Q.6
A ball of mass m moves with speed v and strikes a wall having infinite mass and it returns with same speed then the work done by the ball on the wall is . [BCECE 2004]
  • a) Zero
  • b) m/v.J
  • c) mvJ
  • d) v/m J
Q.7
A block of mass M is attached with a spring of spring constant k. The whole arrangement is placed on a vehicle as shown in the figure, if the vehicle starts moving towards right with an acceleration a ( there is no friction any where) the
ch-5_que_no-217_img_no1.png
  • a)maximum elongation in the spring is (Ma/k)
  • b) maximum elongation in the spring is (2Ma/k)
  • c) maximum compression in the spring is (2Ma/k)
  • d) maximum compression in the spring is (Ma/k)
Q.8
A force F=-k (yi + xj) where k is a positive constant, acts on a particle moving in x-y plane starting from origin, the particle is taken along the positive x-axis to the point (a, 0) and then parallel to the y -axis to the point (a,a). THe total work done by the force F on the particle is [ JEE 98]
  • a) -2ka2
  • b) 2ka2
  • c)-ka2
  • d)ka2
Q.9
A bob of mass M is suspended by a massless string of length L. The horizontal velocity V at position A is just sufficient to make it reach the position B. The angle θ at which the speed of the bob is half of that at A, satisfies .. [ JEE 2008]
ch-5_que_no-219_img_no1.png
  • a)θ=π/4
  • b) π/4 < θ < π/2
  • c)π/2 < θ < 3π/4
  • d)3π/4 < θ < π
Q.10
A particle is moved from (0, 0) to ( a, a) under a force F=( 3i + 4j) from two paths. Path 1 is Op and path 2 is OQP. Let W1 and W2 be the work done by this force in these two paths. Then
ch-5_que_no-220_img_no1.png
  • a) W1=W2
  • b) W1=2W2
  • c) W2=2W1
  • d) W2=4W1
Q.11
A block of mass 0.18 kg is attached to a spring of force constant 2N/m. the coefficient of friction between the block and the floor is 0.Initially the block is at rest and the spring is un-starched. An impulse is given to the block as shown in the figure. The block slides a distance of 0.06m and comes to rest for the first time. the initial velocity of the block is m/s is V=N/Then N is [ JEE 2011]
ch-5_que_no-221_img_no1.png
  • a)1.8
  • b) 4
  • c)2
  • d)3.6
Q.12
An ideal spring with spring constant k is hung from the celling and a block of mass M is attached to its lower end. The mass is released with the spring initially stretched. Then the maximum extension in the spring is [ JEE 2002]
  • a) 4Mg/K
  • b) 2Mg/k
  • c)Mg/k
  • d)Mg/2k
Q.13
A light inextensible string that goes over a smooth fixed pulley as shown in the figure connected two blocks of masses 0.36kg and 0.72kg. Taking g=10 m/s2, the work done ( in joules) by the string on the block of mass 0.36kg during the first second after the system is released from rest
  • a)8 J
  • b)4 J
  • c)16 J
  • d)20 J
Q.14
A rubber ball of mass m and radius r is submerged into water of density ρ to a depth h and released. To what height the ball will jump above the surface of water? Disregard the resistance of water and air?
  • a)
    ch-5_qn-224choice_img_no1.png
  • b)
    ch-5_qn-224choice_img_no2.png
  • c)
    ch-5_qn-224choice_img_no3.png
  • d)
    ch-5_qn-224choice_img_no4.png
Q.15
With what minimum speed v must a small ball should be pushed inside a smooth vertical tube from height h so that it may reach the top of the tube? Radius of the tube is R
ch-5_que_no-225_img_no1.png
  • a)
    ch-5_qn-225choice_img_no1.png
  • b)
    ch-5_qn-225choice_img_no2.png
  • c)
    ch-5_qn-225choice_img_no3.png
  • d)
    ch-5_qn-225choice_img_no4.png
Q.16
An object is thrown straight up. Which of the following is true about the sign of work done by the gravitational force while the object moves up and then down?
  • a)Work is positive on the way up, work is positive on the way down
  • b)Work is negative on the way up, work is negative on the way down
  • c)Work is negative on the way up, work is positive on the way down
  • d)Work is positive on the way up, work is negative on the way down
Q.17
A particle is given an initial speed u inside a smooth spherical shell of radius R=1 m that it is just able to complete the circle. Acceleration of the particle when its velocity become vertical is
ch-5_que_no-227_img_no1.png
  • a) g√10
  • b) g
  • c)g√2
  • d)g√6
Q.18
Which of the following is not a unit for power?
  • a) joule – second
  • b) watt
  • c) newton-meter per second
  • d) horsepower
Q.19
If the momentum of a body is increased n times, its kinetic energy increases
  • a)n times
  • b) √n times
  • c)2n times
  • d)n2 times
Q.20
If the system in the figure is released from rest in the configuration shown, find the velocity of the block Q after it has fallen through a distance 10 metres, given mass of P=mass of Q=10 kg
ch-5_que_no-230_img_no1.png
  • a) 8 m/sec
  • b) 8.85 m/sec
  • c)9.5 m/sec
  • d)10 m/sec
Q.21
The work done against gravity in taking 10 kg mass at 1m height in 1sec will be . [RPMT 2000]
  • a)49 J
  • b)196 J
  • c)98 J
  • d)None of these
Q.22
A body of mass 10kg at rest is acted upon simultaneously by two forces 4 N and 3N at right angles to each other. The kinetic energy of the body at the end of 10 sec is . [Kerala (Engg.)]
  • a) 100 J
  • b) 50 J
  • c) 300 J
  • d) 125 J
Q.23
A bomb of 12 kg divides in two parts whose ratio of masses is 1:If kinetic energy of smaller part is 288 J, then momentum of bigger part in kgm/sec will be
  • a) 37
  • b)72
  • c)108
  • d)Data is incomplete
Q.24
The potential energy of a conservative system is given by U(X)=(x2 - 5x) J.Then the equilibrium position is at....... (where x in m)
  • a)x=1.5 m
  • b)x=2m
  • c)x=2.5 m
  • d)x=5 m
Q.25
Two particles 1 and 2 are allowed to descend on two friction less chord OP and OQ. the ratio of the speeds of the particles 1 and 2 respectively, when they reach on the circumference is
ch-5_que_no-235_img_no1.png
  • a) 1/4
  • b) 1/2
  • c)1
  • d)1/2√2
Q.26
The potential energy of a particle varies with distance x as shown in the graph. The force acting on the particle is zero at
ch-5_que_no-236_img_no1.png
  • a) C
  • b) B
  • c) B and C
  • d) A and D
Q.27
A man starts walking from a point on the surface of earth (assumed smooth) and reaches diagonally opposite point. What is the work done by him . [DCE 2004]
  • a)Zero
  • b)Negative
  • c)Positive
  • d)Nothing can be said
Q.28
Two bodies of masses m and 2m have same momentum. Their respective kinetic energies E1 and E2 are in the ratio . [MP PET 1997; KC]
  • a)1 : 2
  • b)1 : √2
  • c)2 : 1
  • d)1 : 4
Q.29
The kinetic energy of a body moving a straight line varies with time as shown in fiure. The force acting on the body is
ch-5_que_no-239_img_no1.png
  • a) zero
  • b) constant
  • c)directly proportional to velocity
  • d)inversly proportional to velocity
Q.30
A heavy particle of mass m makes complete revolution in a smooth circular tube in a vertical plane. Its greatest speed is n times the least speed. If the least speed is u, what is the speed at the instant, when it is moving vertically?
  • a)
    ch-5_qn-240choice_img_no1.png
  • b)
    ch-5_qn-240choice_img_no2.png
  • c)
    ch-5_qn-240choice_img_no3.png
  • d)
    ch-5_qn-240choice_img_no4.png
0 h : 0 m : 1 s