Physics Work and Energy Question?

A 1000 kg car is moving along a straight road at #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?

2 Answers
Jun 24, 2018

#W = Fx = 200* 1000 = 2*10^5 " 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")#