Question

A 1430 kg car speeds up from 7.50 m/s to 11.0 m/s in 9.30 s. Ignoring friction, how much power did that require?(unit=W)PLEASE HELP

Answer 1

Answer:

4982.8 W

Explanation:

Given the mass of the car = 1430 kg

initial speed = 7.5m/sec

final speed = 11.0 m/sec

time = 9.30sec

Assuming constant accelration a We know that

v=u+at

11=7.5+9.3a

a=0.376 $m/sec^2$

We know that F=ma

F= $1430*0.376 = 538.2N$

We know that $v^2-u^2=2as$

$11^2-7.5^2=2*0.376*s$

s= 86.10m

We know that work(W)=$F*s$

W= $538.2*86.10$ = 46339.02J = 46.34KJ

We know that power= $\frac{work}{time}$ = $\frac{46.34}{9.3}=4.982$ KW