# Hi, I really need help with my homework

1. Nov 6, 2009

### hanagasumi

Hi, I really need help with my homework!!!

I had a home work, it is like:
I have a data table, that has

Initial Position: 1.652m from the sensor
Final Position: 0.977m from the sensor

Initial Velocity: 0.003m/s
Final Position: 1.366m/s

Angle: 27 degrees
g = -9.8m/s^2

U represent the variable for coefficient of friction

The question asks me to find the coefficient of friction, by using the formula according to the potential energy, it's like

gh= v^2+ UcosAngle*d*g

2. Nov 6, 2009

### rock.freak667

Re: Hi, I really need help with my homework!!!

Just use

$$\frac{1}{2}mv^2 + F_R d = mgh$$

and find the frictional force FR and then see how FR relates to the coefficient of friction.

3. Nov 7, 2009

### hanagasumi

Re: Hi, I really need help with my homework!!!

thank you !!!