Say a person weighing 70 kg. is standing on a scale in an elevator in free fall.

Question

Say a person weighing 70 kg. is standing on a scale in an elevator in free fall. Assume no friction whatsoever. What is the weight of this person (both direction and magnitude), the normal force by the scale on the person (both direction and magnitude), and what does the scale read (in kg.)?

Now, the only force now acting on this person is the force of gravity, which is equal to the person's mass multiplied by the acceleration of the elevator, which in free fall would be 9.81 m/s2.  So, the force acting on the person is approximately 686.7 N.  Would this be the person's weight?  Or is there no weight in free fall? 

For the second two questions, since the elevator is in free fall, the person is not going to be able to stand on the scale, so the normal force on the person by the scale should be 0 and same with what the scale reads, correct?

Thanks for the help!

Explanation / Answer

The weight of the person would be 686.7 N, but the scale would read zero. There is weight in free fall, because gravity is still acting on the object. It only seems weightless, which is called apparent weightlessness.

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