Q.1
A bullet of mass 10g moving horizontally with a velocity of 400 ms–1 strikes a wooden block of mass 2 kg which is suspended by a light inextensible string of length 5 m. As a result, the centre of gravity of the block is found to rise a vertical distance of 10 cm. The speed of the bullet after it emerges out horizontally from the block will be :-
  • a) 120 ms–1
  • b) 160 ms–1
  • c) 100 ms–1
  • d) 80 ms–1
Q.2
A particle moves from a point (-2i+ 5j) to (4j + 3k ) when a force of (4i+3j) N is applied. How much work has been done by the force ?
  • a) 5 J
  • b) 2 J
  • c) 8 J
  • d) 11 J
Q.3
This question has statement I and Statement II. Of the four choice given after the statements, choose the one that best describes the two statements. Statement – I : A Point particle of mass m moving with speed v collides with stationary point particle of mass M. If the maximum energy loss possible is given as Statement – II : Maximum energy loss occurs when the particles get stuck together as a result of the collision.
ch-5_que_no-248_img_no1.png
  • a) Statement - I is true, Statement - II is true, statement - II is a correct explanation of Statement - I
  • b) Statement - I is true, Statement - II is true, statement - II is not a correct explanation of Statement – I
  • c) Statement - I is true, Statement - II is false
  • d) Statement – I is false, Statement – II is true
Q.4
The work done on a particle of mass m by a force (K being a constant of appropriate dimension), when the particle is taken from the point (a, 0) to the point (0, a) along a circular path of radius a about the origin in the x-y plane is … [ IIT Advance 2013]
ch-5_que_no-249_img_no1.png
  • a)
    ch-5_qn-249choice_img_no1.png
  • b)
    ch-5_qn-249choice_img_no2.png
  • c)
    ch-5_qn-249choice_img_no3.png
  • d) zero
Q.5
raph A small block of mass 1 kg is released from rest at the top of a rough track. The track is a circular arc of radius 40 m. The block slides along the track without toppling and a frictional force acts on it in the direction opposite to the instantaneous velocity. The work done in overcoming the friction up to the point Q, as shown in the figure below, is 150 J. (Take the acceleration due to gravity, g = 10 ms−2). [ IIT Advance 2013] Q250A) The speed of the block when it reaches the point Q is ..
ch-5_que_no-250_img_no1.png
  • a) 5 ms−1
  • b) 10 ms−1
  • c) 10√3 ms−1
  • d) 20 ms−1
Q.6
A tennis ball is dropped on a horizontal smooth surface. It bounces back to its original position after hitting the surface. The force on the ball during the collision is proportional to the length of compression of the ball. Which one of the following sketches describes the variation of its kinetic energy K with time t most appropriately? The figures are only illustrative and not to the scale. [ IIT Advance 2014]
  • a)
    ch-5_qn-252choice_img_no1.png
  • b)
    ch-5_qn-252choice_img_no2.png
  • c)
    ch-5_qn-252choice_img_no3.png
  • d)
    ch-5_qn-252choice_img_no4.png
Q.7
A particle of mass 10g is kept on the surface of a uniform sphere of mass 100kg and radius 10cm. Find the work done against the gravitational force between them to take the particle far away from the sphere ( G=6.67 × 10⁻¹¹ Nm2 / kg2 ) [ AIIMS 2008]
  • a)3.33 × 10⁻¹⁰ J
  • b) 13.34 × 10⁻¹⁰ J
  • c)6.67 × 10⁻¹⁰ J
  • d)6.67 × 10⁻⁹ J
Q.8
A spring 40 mm long is stretched by applying a force. If 10N force is required to stretch the spring through one mm, then work done in stretching the spring through 40mm is [ AIIMS 1998]
  • a)24 J
  • b) 8 J
  • c)56 J
  • d)54 J
Q.9
A child builds a tower from three blocks. The blocks are uniform cubes of side 2cm. The block are initially lying on the same horizontal surface and each block has a mass of 0.1kg. The work done by the child is
  • a) 4 J
  • b) 0.04 J
  • c)6 J
  • d)0.06 J
Q.10
When a spring is stretched by 2 cm, it stores 100 J of energy. If it is stretched further by 2 cm, the stored energy will be increased by . [Orissa JEE 2002]
  • a)100 J
  • b) 300 J
  • c)200 J
  • d)400 J
Q.11
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
0 h : 0 m : 1 s