Answer: 40.2 hp
Explanation:
The mass of the car is 2000kg.
in 21 seconds, it accelerates from 0m/s to 25m/s, so the average acceleration is:
a = (25m/s)/(21s) = 1.2 m/s^2
We know that force = mass*acceleration, then:
F = 2000kg*1.2m/s^2 = 2400N.
Now, the Power can be written as:
P = W/t where W is work = F*d (force per distance) and t is time.
then we have:
P = (F*d)/t and d/t is the average velocity, and we know the velocity v = 25m/s, so the average velocity will be (1/2)*25m/s = 12.5m/s
P = F*12.5m/s
and the force is F = 2400N
P = 2400 N*12.5m/s = 30,000 W
and we know that 1hp = 746 W
then, P = (30,000/746) hp = 40.2 hp