Question

A man weighs 80 kg. He stands on a weighing scale in a lift which is moving upwards with a uniform acceleration of 5 m/s². What would be the reading on the scale ? (g = 10 m/s²)

(a) zero

(b) 400 N

(c) 800 N

(d) 1200 N

Answer 1

Correct option (d) 1200 N

Explanation:

When the lift is accelerating upwards with acceleration a, then reading on the scale

R = m(g + a) = 80 (10 + 5) N = 1200 N.