Question

A 60 kg man stands on a spring scale in a lift. At some instant he finds that the scale reading has changed from 60 kg to 50 kg for a while and then comes back to the original mark . What should he conclude?

• A. The lift was in constant motion upwards
• B. The lift was in constant motion downwards
• C. The lift while in motion upwards, suddenly stopped
• D. The lift while in motion downwards, suddenly stopped

Answer 1

Answer: (C)

The lift while in motion upwards, suddenly stopped

Answer 2

When lift is moving in the upward direction with retardation, then apparent weight = M[g + (–a)]

i.e. apparent weight < Mg

and when lift is finally stopped then apparent weight = Mg.