# Determining the weight of an object, given force to move it

1. Feb 24, 2010

### Bearbull24.5

1. The problem statement, all variables and given/known data
This is the second part of a problem. In the first problem I determined friction coefficient of an 8N block requiring 2.9 N of force to move is .3625.

The second part of this problem asks: If a weight is added to the block and it now requires 5.7 N to move both at a constant acceleration, what would the weight of the block be?

2. Relevant equations
w=mg
f=uN
u=f/N

3. The attempt at a solution

I attempted to use the friction coefficient I found in the first problem and set it up as N=f/u. This provided me with the wrong answer.

2. Feb 24, 2010

### Staff: Mentor

That method should work just fine, assuming you understand how N relates to the answer they want. Are they asking you to provide the amount of weight added to the block?

3. Feb 24, 2010

### Bearbull24.5

The way the question is set up I believe they want the total weight

4. Feb 25, 2010

### Staff: Mentor

To get the total weight of the block plus whatever was added, the method you showed would be correct.

The wording of the question seemed a bit ambiguous to me--they could also have been asking for the weight added to the block.