# Block slides along an elevated track

1. Nov 24, 2009

### Slimsta

1. The problem statement, all variables and given/known data
A block slides along an elevated track. The flat part has a length L = 0.2m and the object is released from rest from height h = 0.1m. The curved portion of the track is frictionless, but the flat part is rough with a friction coefficient μk = 0.15. Where does the object finally come
to rest? *Hint: use pseudowork to account for friction.
http://img694.imageshack.us/img694/9565/dsfm.jpg [Broken]

2. Relevant equations
U = mgh =m9.8*0.1

3. The attempt at a solution
i know that the object starts with U = mgh =m9.8*0.1=m0.98 but i have no idea what to do next.. and whats pseudowork?

Last edited by a moderator: May 4, 2017
2. Nov 24, 2009

### jdwood983

I had to google it myself, but apparently pseudowork is given by

$$\Delta K_{trans}=\frac{1}{2}mv_{cm}^2=\int \mathbf{F}\cdot d\mathbf{r}$$

where the cm=center of mass. True work is given by

$$W=\int\mathbf{F}\cdot d\mathbf{r}$$

My guess is you'll be using the frictional force for $\mathbf{F}=\mu_k\mathbf{F}_{normal}$ and solving for $\mathbf{r}$ since you will know everything else.