Question

Choose the correct alternative:

1. When a conservative force does positive work on a body, the potential energy of the body increases/ decreases/remains unaltered.

2. Work done by a body against friction always results in a loss of its kinetic/potential energy.

3. The rate of change of total momentum of a many particle system is proportional to the external force/sum of the internal forces on the system.

4. In an inelastic collision of two bodies, the quantities which do not change after the collision are the total kinetic energy/total linear momentum/ total energy of the system of two bodies.

Answer 1

1. decreases

2. kinetic energy

3. external force

4. total linear momentum and also total energy (if the system of two bodies is isolated).