Question

A man of mass $m$ is on the floor of a lift. Match the following.

List I	List II
a) Lift is moving up with acceleration a	e) Apparent weight is greater than true weight
b) Lift is moving down with acceleration a	f) Apparent weight is zero
c) Lift is moving with uniformly velocity	g) Apparent weight is equal to true weight
d) Lift is freely falling	h) Apparent weight is less than true weight

• A. a-e, b-h, c-f, d-g
• B. a-h, b-e, c-g, d-f
• C. a-e, b-h, c-g, d-f
• D. a-e, b-f, c-g, d-h

Answer 1

Answer: (C)

When lift accelerates up, pseudo force acts downwards, hence it increases apparent weight. [a-e]
When lift accelerates down, pseudo force acts upwards, hence it decreases apparent weight [b-h]
When lift moves with uniform velocity there is no pseudo force, hence there is no change in weight. [c-g]
When lift falls freely, it accelerates with g downwards, causing an upwards pseudo force in the frame of the lift equal to mg. Hence total force is 0. So weight is 0. [d-f]