# Static and Kinetic Friction

1. Oct 13, 2009

### krazy19812

Hey guys, im having a little brain fart here, any help? Easy stuff

Im trying to find the static and kinetic friction of an object on a certain surface. We used a modified atwood's machine and got the following results:

Static mass required: 360g
Kinetic mass required: 250g

The mass on the table was 1 kg.

Can someone help me out? and i would love to see some work also..

2. Oct 13, 2009

### krazy19812

Also here is some spitballing i have been doing

$$\Sigma$$Fy=F$$_{N}$$-F$$_{G}$$=0
=> F$$_{N}$$=F$$_{G}$$= ma

I got 9.8m/s$$^{2}$$? not sure if thats right

3. Oct 13, 2009

### rl.bhat

Can you write down the expression for the frictional force?

4. Oct 13, 2009

### krazy19812

$$\mu$$$$_{s}$$ma

i believe it is where mu sub s is the static coefficient

5. Oct 13, 2009

### rl.bhat

Mass is on the table and weight is hanging. Is it so?
In the given problem, what is the frictional force? And what is the normal reaction?