How Much Work is Needed to Pull a Skier Up a Slope?

[kmart47]

a skier of mass 72.9 kg is pulled up a slope by a motor-driven cable. The acceleration due to gravity is 9.81 m/seconds squared. How much work is required to pull the skier 63.5 m up a 34 degree slope (assumed to be frictionless) at a constant speed of 2 m/seconds squared. Answer in units of J.



HELP me out please

 

[tim_lou]

calculate the change in gravitational energy.
where must this energy come from?