Consider a Porsche Cayman...

Question

Consider a Porsche Cayman with a mass of 1,301 kg having a constant acceleration of 5.64 m/s2. What is the power, in hp, exerted by the engine of the car if the speed is 183 m/s?

Answer: 1,799.98

Answer 1

Power is the rate of change of energy. In this case the car has kinetic energy, KE = 1/2 mV².

The rate of change of KE can be obtained by taking the derivative of the KE with respect to time.

d KE / dt = 1/2 x m x 2 x V x dV/dt. dV/dt is the acceleration and 2 cancel out, so the equation becomes dKE/dt = P = 1301 kg x 183 m/s x 5.64 m/s² = 1.34 x 10⁶ watts.

Convert this to hp by dividing by the watt to hp conversion factor.