Question

Which one of the following person is in an inertial frame of reference?

Options

• A person (man) in a train which is slowing down to stop.

• A person (child) revolving in a merry-goround.

• A person (driver) in a bus which is moving with constant velocity.

• A person (pilot) in an aeroplane which is taking off.

Answer 1

A person (driver) in a bus which is moving with constant velocity.

Explanation:

An inertial frame of reference is one that moves with constant velocity (zero acceleration), and a bus moving at constant velocity has no acceleration, unlike a slowing train (A), a merry-go-round with centripetal acceleration (B), or a taking-off aeroplane (D), all of which are non-inertial frames.