A 850-kg sports car accelerates from rest to 95 km/h in 5.0 s .

Question

A 850-kgkg sports car accelerates from rest to 95 km/hkm/h in 5.0 ss . What is the average power delivered by the engine?

Express your answer to two significant figures and include the appropriate units.

Answer 1

95 km/h = 95000 m / h = 95000 / 3600 m/s

Kinetic energy = 1/2 m v² = 0.5 x 850 x (95000 / 3600)²

Power = energy / time = kinetic energy / 5.0 (units of power are W or J/s)