# Homework Help: Why would his weight be zero at the moment of the fall?

1. May 2, 2016

### alaa amed

1. The problem statement, all variables and given/known data

A person of weight w is in an upward-moving elevator when the cable suddenly breaks. What is the person's apparent weight immediately after the elevator starts to fall?

2. May 2, 2016

### Staff: Mentor

How would you personally define the term "apparent weight?"

3. May 2, 2016

### alaa amed

I think that's the key to answering the question, though I am not sure I interpreted properly. I think it means the weight relative to the force of gravity that acts on it in particular instance.

4. May 2, 2016

### Staff: Mentor

That's not correct. It means that, if he was standing on a scale, what the scale would read (i.e., the normal force the person would be exerting on the scale, and, by Newton's 3rd law, the normal force the scale would be exerting on the person). That's the definition of his apparent weight.

So, what is the normal force that the scale is exerting on the person if the elevator cable has been cut?

5. May 2, 2016

### alaa amed

I think the person and the elevator would be free falling an so there would be no contact force?

6. May 2, 2016

### Staff: Mentor

Yes. That is correct. So what does that mean regarding the "apparent weight" of the person, considering the apparent weight is equal to the contact force.

7. May 2, 2016

### alaa amed

It will be zero! Thank you so much for your help.
I get it now.