A student is investigating the effect on her wight when travelling in a lift. She is standing on scales which are graduated in Newtons.?

A student is investigating the effect on her wight when travelling in a lift. She is standing on scales which are graduated in Newtons. When the lift is not moving, her wight id 600 N. What will be the reading on the scales when the lift is moving upwards with a constant velocity of 4 m/s?

1 Answer
Jun 11, 2018

600 N

Explanation:

As the student is moving (along with the lift) at constant velocity, she is not accelerating and thus the net force on her must be zero. Thus, the force that the spring balance exerts on her must be equal and opposite to her weight. Its reaction, the force that she exerts on the spring balance, must then be equal to her weight - i.e. 600 N.