A roller coaster (mass MRC = 596 kg) is moving with speed of 29.7 m/s as it moves over a crest 28.9 m above the ground. It then travels along a 41 m stretch of track that creates an average frictional force of 70.2 N regarding the motion. At the end of this stretch the roller coaster is only 6.1 m above the ground.

What is the speed (in m/s) of the roller coaster when it reaches the 6.1 m height?