Question

A 1500-kg car accelerates from 0 to 25 m/s in 7.0 s with negligible friction and air resistance. what is the average power delivered by the engine? (1 hp = 746 w)

Answer 1

Average power=89.8 hp

Step-by-step explanation:

According to work energy theorem,

Work done= change in kinetic energy

W= 1/2 m Vf²-1/2 m Vi²

m= mass= 1500 Kg

Vi= initial velocity=0

Vf= final velocity= 25 m/s

w= 1/2 (15000(25)²- 1/2 (1500)(0)²

W=468750 J

now power= work / time

P=468750/7

P=66964 W= 66964/746=89.8 hp

so P=89.8 hp