Physics Work and Energy Question?

A 1000 kg car is moving along a straight road at 25 ms^-125ms1. 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?

2 Answers
Jun 24, 2018

W = Fx = 200* 1000 = 2*10^5 " J"W=Fx=2001000=2105 J

Jun 24, 2018

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

Explanation:

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")