Physics Work and Energy Question?

Question

A 1000 kg car is moving along a straight road at $25 m s^{- 1}$ $25 ms^-1$ . A net force of 200 N acts in a forward direction for a distance of 1.0 km. What is the work done on the car by the net force?

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Answer 1 · 2018-06-24T09:46:50

$W = F x = 200 \cdot 1000 = 2 \cdot 10^{5} J$ $W = Fx = 200* 1000 = 2*10^5 " J"$

Answer 2 · 2018-06-24T13:25:49

$2*10^5 \ "J"=200,000 \ "J"$

Work done is given by the equation:

$W=F*d$

where:

$W$ is the work done in joules

$F$ is the force applied in newtons

$d$ is the distance moved in meters

We got: $d=1 \ "km"$ . Let's convert that to meters. We know that one kilometer is equal to $1000$ meters.

So, we get:

$d=1color(red)cancelcolor(black)"km"*(1000 \ "m")/(color(red)cancelcolor(black)"km")=1000 \ "m"$

So the work done is:

$W=200 \ "N"*1000 \ "m"$

$=200,000 \ "N m"$

$=200,000 \ "J" \ (because 1 \ "N m"-=1 \ "J")$