Question

Find the magnitude of the force P required to move the cabinet to the right (a) if all casters are locked, (b) if the casters at B are locked and the caster at A are free to rotate, (c) if the casters at A are locked and the caster at B are free to rotate.

Answer 1

For case b, you will still have a normal force at caster A since it is still in contact with the ground. There will also be a frictional force at that location but it will be based on mu (kinetic) instead of mu (static)

Answer 2

I took moment about point B because I was trying to find another equation I could use to solve simultaneous equations.

Answer 3

Your previous statement makes sense. So I could solve this problem using mew of k and mew of s in the equations.

Answer 4

Good...for case b, if you are just at the point of impending motion, at roller b, the force of friction is at a maximum of mu (static) *Nb. But if that is the case, then at A you can only have a normal force because that wheel can't be rotating.

Answer 5

So there is only a normal force at point A? No Fm?

Answer 6

yes

Answer 7

Okay there is a part (c) to this problem I am going to work on in a few. I've got to go. If I've got anymore questions I will ask you, thanks.

Answer 8

ok