The following examples can be exciting, at the same time educative too:
(a) The heat energy of steam runs an engine.
(b) The study of electricity and magnetism helps us to design dynamos and motors.
(c) The beating of the drum causes vibrations, producing huge sound,can pollute air and even make people mad and deaf.
(d) The fall of an apple leads us to understand gravity
(e) A spherical liquid drop, and it never takes any other geometrical shape, helps us to understand surface tension.
