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

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

Step-by-step 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