A stack of books whose true weight is 165 N is placed on a scale in an elevator. The scale reads 165 N. Can you tell from this information whether the elevator is moving with a constant velocity of 2 m/s upward or 2 m/s downward or whether the elevator is at rest?

A) the elevator is moving with a constant velocity of 2 m/s upward

B) the elevator is moving with a constant velocity of 2 m/s downward

C) the elevator is at rest

D) not enough information to decide

D) not enough information to decide

Explanation:

Data provided in the question

The True weight of book stacks = 165 N

Reading of the scale = 165 N

Constant velocity = 2 m/s upward or downward

Based on the above information

If you moved at a constant velocity the scale interprets the same because of the momentum you've got. The scale will change the number only when acceleration is present.

Therefore in the given situation, the option D is correct as it not have enough information for deciding it