What is the solution to this inclined plane problem?

[drdevil52]

Homework Statement

This problem asks for the angle on an inclined plane-- I have attached the problem below.

Homework Equations

fnet=ma

The Attempt at a Solution

I honestly have no idea what to do. I found the vector components for gravity and made a FBD for the box, but I can't really figure out what the next step is.

 

[billy_joule]

Are you familiar with conservation of energy? You can find the kinetic energy of the block at the bottom of the ramp, this must be equal to the gravitational potential energy at the top of the ramp, you can solve for the height of the ramp, then find theta using trig.

Alternatively, find the acceleration of the block from the distance and the final speed.