# Inclined plane problem

1. Sep 18, 2006

### angeljunti

A car traveling at 25.0m/s runs out of gas while traveling up a 22.0 degree slope.
How far up the hill will it coast before starting to roll back down?

i tried doing (2*25m/s)^2 / cos22*-9.8cos68 but that wasn't the right answer...

Last edited: Sep 18, 2006
2. Sep 18, 2006

### 6Stang7

what equation are you using? have you drawn a force diagram?

3. Sep 18, 2006

### Hootenanny

Staff Emeritus
Alternatively, one could consider the work-energy theorem

4. Sep 18, 2006

### Delzac

When i comes to inclined slope like these part of the g is "filtered" off. Thus Draw out your free body diagram, resolve the g in the direction parrallel to the slope.

then use the formular V^2 = U^2 + 2as

Hope it helps.

EDITED version
sry ><

Last edited: Sep 18, 2006
5. Sep 18, 2006

### Hootenanny

Staff Emeritus
Delzac, please do not post complete solutions.

Edit: No problems Delzac

Last edited: Sep 18, 2006
6. Sep 18, 2006

### 6Stang7

most defiantly, that's how i first looked at it. from the looks of it though they haven't started studying energy yet (at least that's what i think) and i was ify on possible jumping ahead.

7. Sep 18, 2006

### 6Stang7

well, now that the correct formula has been given, does the car accelerate? if so, how would you find the acceleration rate of the car?

8. Sep 18, 2006

### castaway

how can you be sure that the acceleration or retardation here is constant?

9. Sep 18, 2006

### Hootenanny

Staff Emeritus
Is the acceleration due to gravity (approximately) constant here?

10. Oct 25, 2008