Is c) the correct answer for this Mechanical Energy problem?

[temaire]

[SOLVED] Mechanical Energy problem

Homework Statement

http://img517.imageshack.us/img517/7201/dynamics3oi8.jpg

Homework Equations

E_{m}=E_k + E_p

The Attempt at a Solution

I think that the answer to the problem is c), because as the object is moving up, it is slowing down because it has to work against friction and gravity. Also, as the object moves up, it gains height, and therefore gains potential energy. Am I right?

 

[temaire]

Can anyone help?

 

[awvvu]

If there's a net force up the ramp then it has to be accelerating, and therefore KE is increasing.

 

[DylanB]

we don't know where the net force is pointing though, because we don't know the magnitude of all the forces.

the answer depends on whether the forces cause the ball to move up or down the ramp. either way the kinetic energy will be increasing since it was motionless a moment before.

the mechanical energy will be increasing/decreasing depending which way the ball moves.

 

[temaire]

Thanks dylan.