a. V=110km/h = 110000m/3600s.=30.56 m/s
V^2 = Vo^2 + 2g*h
h = (V^2-Vo^2)/2g = (0-(30.56)^2/-19.6 =
47.6 m.
. (a) How high a hill can a car coast up (engine disengaged) if work done by friction is negligible
and its initial speed is 110 km/h? (b) If, in actuality, a 750-kg car with an initial speed of 110 km/h
is observed to coast up a hill to a height 22.0 m above its starting point, how much thermal energy
was generated by friction? (c) What is the average force of friction if the hill has a slope 2.5°
above the horizontal?
1 answer