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?

Answer 1

For upward acceleration apparent weight= m (g + a) If lift suddenly stops during upward motion then apparent weight =m(g-a) because instead of acceleration, we will consider retardation. In the problem it is given that scale reading initially was 60 kg and due to sudden jerk reading decreases and finally comes back to the original mark ie, 60 kg. So, we can conclude that lift was moving upwards with constant speed and suddenly stops.