Find the odd one out a)Planets moving on it's axis, Strings of guitar (being played),Motion of a ferry wheel, The vehicles moving on a straight road. b)Motion of the moon around the earth, Motion of the earth around the sun, Motion of a merry-go-round, Heart-beat in a healthy person. c)Motion of a bullet fired from gun, Motion of a football player in the ground, Motion of a vehicle on a straight road, Motion of an apple falling from a tree

a) Strings of guitar (being played)

b) Heart-beat in a healthy person

c) Motion of an apple falling from a tree

Explanation:

a) The motion of the string of a guitar being played is the only motion involving simple harmonic motion.

b) All the other motions are circular motion except the heart beat in a healthy person, which is periodic.

c) The motion of an apply falling from a tree is the only motion under the complete influence of gravity from the onset till the end.