Write the similarities and differences between the motion of a bicycle and a ceiling fan that has been switched on.

Motion is the change in position of an object with respect to time. There are basically three types of motion. They are rectilinear motion, circular motion and periodic motion.

a) Motion in a straight line is called rectilinear motion.

e.g., motion of a vehicle on a straight road, march-past of soldiers in a parade etc.

b) Motion in a circular path in which distance from a fixed point remains the same is called circular motion.

e.g., motion of a wheel, a stone tied to a string etc.

c) Motion that repeats itself after some period of time is called periodic motion.

e.g., pendulum of a clock, a swing in motion etc.

For the motion of a bicycle and a ceiling fan that has been switched on, their

Similarities are:

(i) The wheels of the bicycle and the blades of the fan are in a circular motion.

(ii) The blades of the fan and spokes of the wheels of the bicycle are fixed at a certain point.

Differences are:

(i) Unlike the fan, the bicycle is in linear motion

(ii) The motion of the blades of the fan is periodic whereas that of the cycle is rectilinear.