Write true or false for each statement:

(a) A coolie does no work against the force of gravity while carrying a luggage on a plane road.

(b) The energy stored in water of a dam is kinetic energy.

(c) The energy of a flying kite is kinetic energy.

(d) Work done by a boy depends on the time in which he does work.

(e) Power spent by a body depends on the time for which it does work.

Match the following:

When does a force perform work?

State two conditions when no work is done by a force.