Question

A driver in a 2000 kg Porsche wishes to pass to pass a slow-moving school bus on a four-lane road. What is the average power in watts required to accelerate the sports car from 30 m/s to 60 m/s in 9 seconds

Answer 1

Answer:

The power require to accelerate the car is, P = 299700 watts

Explanation:

Give data,

The mass of the car, m = 2000 kg

The initial velocity of the sports car, u = 30 m/s

The final velocity of the sports car, v = 60 m/s

The time period of acceleration, t = 9 s

The acceleration of the car, a =  (v-u) / t

                                                  = (60 - 30) / 9

                                                  = 3.33 m/s²

The displacement of the car,

                                               S = ut + ½ at²

                                                  = 30 x 9 + ½ x 3.33 x 9²

                                                  = 405 m

The force acting on the car, F = m x a

                                                  = 2000 x 3.33

                                                  = 6660 N

The work done by the car, W = F  S

                                                  = 6660 x 405

                                                  = 2697300 J

The power of the car,           P = W / t

                                                  = 2697300 / 9

                                                  = 299700 watts

Hence, the power require to accelerate the car is, P = 299700 watts