Motorcycle Power?

Question

A motorcycle and rider have a combined mass of 250 kg and are traveling at a steady velocity of 17 m/sec. The force of wind resistance acting the motorcycle and rider at this speed is 150N.

a) What power must the motorcycle produce to sustain this velocity on level ground?


b) How power must the motorcycle produce to sustain this velocity on an upward incline of 39 degrees?


c) How much energy is produced by the motorcycle in 3 hours of driving on level ground?

Answer 1

Power = work / time
= (force · distance) / time
= force · (distance/time)
= force · speed

Part a): To counteract the 150N of wind resistance, the motorycle must generate a force of 150N in the opposite direction. Force=150N; speed=17m/sec; use the above formula.

Part b): The motorcycle is now counteracting wind resistance plus gravity. The wind resistance is still 150N. Gravity pulls backward (down the slope) with a force of (mg)sinθ. Use the above formula.

Part c): energy = work = (force)(distance) = (force)(speed)(time).