I'm so stuck on this question. Can anyone help me on this one?

At point A (on the ground), a 12.5 kg box is sliding up the slope at 11.2 m/s. At point B (at the peak), the box's speed is now 7.11 m/s. Given that the vertical height between A & B is 3.12m, determine:

a) amount of thermal energy produced while the box is sliding up the slope.
b) distance between pt A & B (Provided that force of friction no the box while sliding up the slope is a constant of 18.3 N.).

Many thanks to whoever tries to solve this question! :)

For a)

Since no more information is given, I'll take this using the law of conservation of energy, where no energy is lost and all the dissipated energy is in the form of heat energy.

Energy (kinetic) at first is given by

Energy at the peak is given by plus the kinectic energy.

The second total energy is less than the first one. The difference gives the heat energy dissipated.

b) Well, work done is Force times displacement in the direction of the force.

The work done on the box is equal in magnitude to its work done. You know the force, find the displacement, which in this case is equal to the distance AB.

:)