Aperson stands on a scale in an elevator and has a weight of 850 newtons. if the
reading on the scale changes to 500 newtons, what is occurring?

Elevator is going down.

Explanation:

Given that,

Weight of the person standing in the elevator, w = 850 N

                                                                       mg= 850 N

The reading changes to                     W = 500 N

The W can be expressed as

                                           W = (g±a)m  N

Since the mass is constant, the value of W can be lowered only by the '-a' value.

The acceleration 'a' is negative for a person who is accelerating towards gravity.

Hence, the elevator is going down.                                

not too sure thinking all accelerations are pointed down