A boy is sitting on a merry-go-round which is moving with a constant speed of 20 ms^-1. This means that the boy is :

A. at rest

B. moving with no acceleration

C. in accelerated motion

D. moving with uniform velocity

A particle is moving in a circular path of radius r. The displacement after a circle would be:

A. 0

B. pr

C. 2r

D. 2pr

The numerical ratio of displacement to distance for a moving object is :

A. < 1

B. = 1 or > 1

C. > 1

D. = 1 or < 1

In which of the following cases of motion, the distance moved and the magnitude of displacement are equal?

A. if the car is moving on straight road

B. if the car is moving on circular road

C. if the pendulum is moving to and fro

D. if a planet is moving around the sun

The speed of a moving object is determined to be 0.12 m/s. This speed is equal to :

A. 2.16 km/h

B. 1.08 km/h

C. 0.432 km/h

D. 0.0216 km/h