CBSE
Multiple Choice Questions300 J of work is done in sliding a 2 kg block up an inclined plane of height 10 m. Taking g =10 m/s2, work done against friction is
200J
100 J
zero
1000 J
Two spherical bodies of masses M and SM and radii R and 2R respectively are released in free space with initial separation between their centres equal to 12 R. If they attract each other due to gravitational force only, then the distance covered by the smaller body just before collision,
1.5 R
2.5 R
4.5 R
7.5 R
The potential energy of a body is given by U = A - Bx2 (where x is the displacement ) The magnitude of force acting on the particle is
constant
proportional to x
proportional to x2
inversely proportional to x
A motor cycle is going on an overbridge of radius R. The driver maintains a constant speed. As the motor cycle is ascending on the overbridge, the normal force on it
increases
decreases
remains the same
fluctuates erratically
A ball is released from certain height which losses 50% of its kinetic energy on striking the ground it will contain a height again
of initial height
of initial height
th of initial height
None of the above
A ball of mass 2 kg moving with velocity 3 m/s collides with spring of natural length 2 m and force constant 144 N/m. What will be length of compressed spring?
2 m
1.5 m
1 m
0.5 m
A gas expands 0.25 m3 at constant pressure 103 N/m2, the work done is
250 N
250 W
250 J
2.5 erg
The work done by a force acting on a body is as shown in the graph. The total work done in covering an initial distance of 20 m is
225 J
200 J
400 J
175 J
If we throw a body upwards with velocity of 4 m/s, at what height does its kinetic energy reduce to half of the initial value? ( Take g = 10 ms-1 )
4 m
2 m
1m
0.4 m
A body of mass m1 = 4 kg moves at 5 i m/s and another body of mass m2 = 2 kg moves at 10 i m/s. The kinetic energy of centre of mass is
