First, we need to convert Wh to joules. This can be easily done. Wh means that you are doing 1W of work per hour. We need to find out how much work this is.
We lost 60% of this energy on friction and other losses which means that this leaves us with:
We are going to use this energy to do work against the force of gravity. This means that when we reach our maximum height all of our energy will be used and thus converted the potential energy in the gravitational field.
