The quantities remaining constant in a collision are:

1.	momentum, kinetic energy and temperature
2.	momentum and kinetic energy but not temperature
3.	momentum and temperature but not kinetic energy
4.	momentum, but neither kinetic energy nor temperature

In an elastic collision:

In an inelastic collision:

A block moving in air breaks into two parts and the parts separate;

(a) the total momentum must be conserved

(b) the total kinetic energy must be conserved

(c) the total momentum must change

(d) the total kinetic energy must change

Choose the correct options:

1. (a) and (b)

2. (a) and (c)

3. (a) and (d)

4. All of these

In an elastic collision:

Choose the correct options:

A ball hits a floor and rebounds after an inelastic collision. In this case:

(a) the momentum of the ball just after the collision is same as that just before the collision

(b) the mechanical energy of the ball remains the same during the collision

(c) the total momentum of the ball and the earth is conserved

(d) the total energy of the ball and the earth remains the same

Choose the correct options:

1. (a) and (b)

2. (b) and (c)

3. (c) and (d)

4. None of these

A body moving towards a finite body at rest collides with it. It is possible that:

(a) both the bodies come to rest

(b) both the bodies move after the collision

(c) the moving body comes to rest and the stationary body starts moving

(d) the stationary body remains stationary, the moving body changes its velocity

Choose the correct options:

1. (a) and (b)

2. (b) and (c)

3. (c) and (d)

4. All of these

In a head-on elastic collision of two bodies of equal masses:

(a) the velocities are interchanged

(b) the speeds are interchanged

(c) the momenta are interchanged

(d) the faster body slows down and the slower body speeds up

Choose the correct options:

1. (a), (b) and (c)

2. (b), (c) and (d)

3. (a) and (b)

4. All of these

A body at rest breaks into two pieces of equal masses. The parts will move:

A ball kept in a closed box moves in the box making collisions with the walls. The box is kept on a smooth surface. The velocity of the centre of mass: