1. What is non conservative force give one example.
2. Show the total mechanical energy of a freely falling body remains constant.
3. State the principle of conservation of mechanical energy.
4. A girl of mass 40 kg seats in a swing formed by a rope of 6 m length . A person pushes the swing to a side so that roop makes an angle 60 degree with the vertical. What is the gain in potential energy of the girl?
5. Derive the expression for work done by a spring force and show that spring force is a conservative force and also write the expression for potential energy of an elastic stressed spring.
6. If a block attached to a spring ( Whose other end is recently fixed ) is pulled up to distance x and released, the amplitude of its motion cannot exceed ± x why ?
7. Can there be a situation in which E - U < 0 ? Explain.
8. A uniform chain of length l and mass m is lying on a smooth table and one third of its length is hanging vertically down over the edge of the table. If g is acceleration due to gravity, calculate the work required to pull the hanging part on the table.
9. A body of mass 2 kg initially at rest moves under the action of an applied horizontal force of 7 Newton on a table with coefficient of kinetic friction equal to 0.1. compute the
a) applied force in 10 second ,
b) work done by the friction in 10 second?
c) work done by the net force on the body in 10 second and ,
d) change in kinetic energy of the body in 10 second. interpret your result.
10. Derive the relation between potential energy and conservative force.
