physics
posted by Yuli .
A 65.0kg skier coasts up a snowcovered hill that makes an angle of 27.4° with the horizontal. The initial speed of the skier is 6.37 m/s. After coasting 2.07 m up the slope, the skier has a speed of 4.06 m/s. Calculate the work done by the kinetic frictional force that acts on the skis.
can someone explain this question to me please?

height gained = h = 2.07 sin 27.4
Potential energy gained = m g h
Ke lost = (1/2)m (6.37^2  4.06^2)
work done by friction = difference