Question

A car of mass 1000 kg is moving at a speed of 90 km h–1. Brakes are applied and the car stops at a distance of 15 m from the braking point. If the car stops in 25 s after braking, calculate the average power of the brakes?​

Answer 1

Pavg =24.4×20800

Step-by-step explanation:

1st u(initial velocity)=90×5/18=25m/s

v^2-u^2=2as........v=0

a=-20.8 then force=ma =1000×(-20.8)=-20800

P initial=f×u and P final=f×s/t

Pavg=Pi-Pf=fu-fs/t=f(25-15/25)=f(25-0.6)

Pavg=20800×24.4