finding how much power at final

Question

A car engine produces a constant power of P = 350 hp. The car and motor have a combined mass of m = 2200 kg.

A top fuel dragster of mass m = 1000.0 kg can accelerate and cover 305 m in 4.15 secs from a dead stop. How much horsepower is the engine producing at the wheels at the end of the race, assuming the acceleration is constant?

Answer 1

power p, force F,· mass m, velocity v and acceleration a has the relation:

p = F·v = m·a·v,

The travel of an object start from 0 at constant acceleration a for time t is:

, so , and the end speed v is .

The power P is then:. with the value of m=1000kg, d=305m, t=4.15,

we have P=5.206×10⁶ W = 5206 kW = 7078 hp.