QUESTION 3 (copy final answers with units only to each part) (8 marks) 3. A rollerblade of mass m = 4.97 kg is released from rest from position J and slides down the frictionless track as shown in the figure. The height h at each position is: 4 h(J) = 4.70 m h( k ) = 2.90 m h(L) = 1.70 m h( J ) h ( k) h ( ) a) Determine the speed of the rollerblade at position K. b) Determine the net work done on the rollerblade by gravity as it moves from position J to position L. c) If instead the skate is dropped from rest at height J and allowed to free-fall to height L with air resistance F air = 1.2 N, what is the work done by air resistance? Type answer for part a (final answer with units only)