(a) the unwinding of a watch spring

(b) a loaded truck when started and set in motion,

(c) a car going uphill,

(d) photosynthesis in green leaves,

(e) charging of a battery,

(f) respiration,

(g) burning of a match stick,

(h) explosion of crackers.

Solutions:

(a) The potential energy of a watch spring becomes kinetic energy

(b) The chemical energy of diesel or petrol becomes mechanical energy

(c) Kinetic energy becomes potential energy

(d) Light energy becomes chemical energy

(e) Electrical energy becomes chemical energy

(f) Chemical energy becomes heat energy

(g) Heat and light energy are created when chemical energy is converted

(h) Heat, light, and sound energy are all converted from chemical energy.