# Homework Help: Energy conservation answer check

1. Apr 3, 2009

### Jack21222

1. The problem statement, all variables and given/known data

A 1500kg rocket is to be launched with an initial upward velocity of 50m/s. In order to assist its engines, engineers will start it from rest on a ramp that rises 53 degrees from the horizontal. At the bottom, the ramp turns upward and launches the rocket vertically. The engines provide a constant forward thrust of 2000 N, and friction with the ramp is a constant 500 N. How far from the base of the ramp should the rocket start, as measured along the surface of the ramp?

2. Relevant equations

E0 +Win = Ef + Elost
U = mgh
KE = 1/2 m v2

3. The attempt at a solution

I need to find the displacement along the ramp. I made the change in x the surface of the ramp, and I made h equal x*sin 53.

Solving for x, I got 141.6m.

2. Apr 3, 2009

### Staff: Mentor

Looks good.

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