Need physics help!

[ama146]

This is probably trivial for most of you, but I am struggling with physics and this is a take-home quiz. I really don't know where to start on this so I thought maybe someone on here can point me in the right direction. Thanks for any help!

P.S. I'm not looking for someone to do the problem for me, I just need someone to explain HOW to solve it and maybe the formulas needed, etc.

Edited February 22, 2012 by ama146

[CBBaron]

F = m*a

Thats all you need.

[ama146]

I thought of that but it doesn't make sense to me. If I use that formula on letter "B" for example, that comes out to be -122.4N. It is asking for scale weight, so how can scale weight be a negative number?

[blue03636]

velocity is useless in this.

the 600N = the weight of the person*9.8

if the acceleration of the elevator is up you will subtract that to 9.8 as the force will be higher on the scale therefor you will add the acceleration from 9.8 if the elevator is going down. Any that have 0 acceleration will just have the 9.8. Looks like you will a few that are the same answer.

Edited February 22, 2012 by blue03636
backwards

[CBBaron]

velocity is useless in this.

the 600N = the weight of the person*9.8

if the acceleration of the elevator is up you will subtract that to 9.8 as the force will be higher on the scale therefor you will add the acceleration from 9.8 if the elevator is going down. Any that have 0 acceleration will just have the 9.8. Looks like you will a few that are the same answer.

Your signs are wrong but otherwise precisely.

Craig

[blue03636]

Your right, you have to find the initial weight to multiply it by te adjusted gravity.

Edited February 22, 2012 by blue03636