2 A 250 kg roller coaster passes point A at 12.0 m/s. A/K v = 12.0 m/s 18.0 m What is the speed of the roller coaster at point B at the bottom of the hill if 8 500 J of energy is transformed to heat during the journey? (7 marks) A 45 kg child on a water slide passes point A at 8.3 m/s. A/K v= 8.3 m/s 21 m As the child descends from A to B, 3 600 J of heat energy is created because of friction. What is his speed at B? (7 marks) 4 As a skier descends a slope, her kinetic energy increases from 600 J to 3 200 J while her gravitational potential energy decreases by 5 900 J. How much heat energy is created due to friction? A. B. 3 300 J 8 500 D. 9 700 J