Ok, here is the problem: A car manufactuerer claims that their car can accelerate from rest to 101 km/hr in 5.6 seconds. The car's mass is 840 kg. Assuming that this performance is achieved at constant power, determine the power developed by the car's engine. Part B) What is the car's speed after 2.8 s? Ok, so first off i changed the 101km/hr to m/s. So it should be 28.1m/s. Then I used the equation: V=Vo + at to find acceleration and so plugging in 28.1m/s=0 + a(5.6s), a= 5.01m/s^2. So since power = F*v, I plugged in P = 840kg*5.01m/s^2*28.1 = 118256.04 W. This is not right. Since the power is constant, I'm thinking that the acceleration is probably not. So how would I incorporate that into my equation?? Once I get that, I can prolly get part B. Thank's for any help at all!