Question

Which of the following examples represent periodic motion?

(a) A swimmer completing one (return) trip from one bank of a river to the other and back.

(b) A freely suspended bar magnet displaced from its N-S direction and released.

(c) A hydrogen molecule rotating about its center of mass.

(d) An arrow released from a bow. 11th physics , chapter-14

Answer 1

(a) There is no repetition of the motion as the swimmer just completed one trip : hence it isn't periodic .

(b) The motion is repeated after a certain interval of time , hence periodic.

(c) Rotatary motion is periodic as repeating after fixed time - interval .

(d) There is no reputation , hence it isn't periodic .