Question

A car is moving along a straight horizontal road. The car has 1.6MJ of kinetic energy. The car accelerates for 20s until the kinetic energy of the car increases to 2.5MJ. What is the minimum average power developed by the car engine for this acceleration?

Answer 1

P = 45 [kW]

Step-by-step explanation:

We must find the difference in kinetic energy during the 20 seconds.

`D_(kE)=2.5-1.6\\D_(kE)=0.9[MJ]`

Power is defined as the relationship between energy over time.

`P=D_(kE)/t\\P=0.9/20\\P=0.045[MW] or 45 [kW]`