How high (in m) a hill can a car coast up (engine disengaged) if friction is negligible and its initial speed is 74.0 km/h? (Enter a number.) m(b)If, in actuality, a 750 kg car with an initial speed of 74.0 km/h is observed to coast up a hill to a height 9.0 m above its starting point, how much thermal energy (in J) was generated by friction? (Enter a number.) J(c)What is the average force of friction (down the slope) if the hill has a slope 2.5 above the horizontal? (Enter your answer in N. Enter a number.)

A 69.8-kg boy is surfing and catches a wave which gives him an initial speed of 1.60 m/s. He then drops through a height of 1.62 m, and ends with a speed of 8.51 m/s. How much nonconservative work (in kJ) was done on the boy?