2. A 1.00 x 103 kg sports car accelerates from rest to 25.0 m/s in 7.50 s. What is the

average power output of automobile engine?

a. 20.8 kW

b. 30.3 kW

C. 41.7 kW

C = 41.7kW

Explanation:

Data ;

Mass (M) = 1x10³kg

Initial velocity (u) = 0m/s

Final velocity (v) = 25m/s

Time (t) = 7.5s

Power = Work / time

Work = force * distance

acceleration = average velocity/ time

Acceleration = (25 - 0) / 7.5 = 3.3m/s²

Power = force * velocity (speed)

Average velocity = (25 - 0) / 2 = 12.5m/s

Force = mass * acceleration = 1x10³ * 3.3 = 3333.33N

Power = force * velocity

Power = 3333.33 * 12.5 / 41666.67W

force is mass*acceleration.

we have a very small mass: 11.4*0.001 kg

if we want 0.035n of force, we need an acceleration:

0.035 = 11.4*0.001*a

a = 0.035/(11.4*0.001) m/s^2