A body of mass 100 g is suspended from a spring balance held by a boy. If the spring balance is allowed to fall freely in air, what will be the reading in the balance ?

What is spring balance?

A spring balance is attached to the roof of a lift. A man hanged his bag from the spring balance. The reading of the spring balance is 49N when the lift is not moving. When the lift will move downward with the acceleration 5m//s^2 , then the reading of the spring balance will be:

The place where spring balance ceases to work is

When a block is suspended in air from a spring balance, it reads 60 N. When the block is immersed completely in water, the spring balance reads 40 N. The specific gravity of the block is