Physics Help- Newton's Laws?

Question

I need to know how to solve the following problem. I don't just want the answer. I need to know and understand the process.

A person stands on a bathroom scale in a motionless elevator. When the elevator begins to move, the scale breifly reads only .75 of the person's regular weight. Calculate the acceleration of the elevator, and find the direction of acceleration.

Answer 1

CanProf's pretty much got it. Force is linear in acceleration:

F = ma

and you're dealing with force here. Your weight is pulling you down, but the acceleration of the elevator is giving you an apparent weight less than your actual weight. Treat it as a net force problem for the scale and do a free body diagram. You will find, though, that he's right.

Answer 2

I'll defer to a physicist on this but it sounds to me like the elevator is accelerating downward at 1/4 of the acceleration due to gravity, i.e. rought 2.45 meters per second per second