answer with explanation for the whole question

1. A pilot jumps from a plane and falls 400 m before landing in a snowbank, coming to rest after creating a 1.5 m deep crater. If the pilot's mass is 80 kg and his terminal velocity was 35 m/s, find (a) the average force exerted by the snow to stop him, and [2] (b) the work done on him by air resistance as he falls. [2]