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

4982.8 W

Step-by-step 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=
`(work)/(time)` =
`(46.34)/(9.3)=4.982` KW