Video Transcript
What average force must be applied to move a computer’s mouse by 0.30 meters if this force does 0.75 joules of work?
In this question, we’ve been given a computer mouse. And this mouse must be moved by 0.30 meters. The work done to move this mouse is 0.75 joules. We’re trying to work out the average force exerted on the mouse. So the three quantities we’re trying to link up together are the distance moved 𝑥, the work done 𝑊, and the force 𝐹.
We can recall that the work done on an object is the force applied to the object multiplied by the distance it moves. Or in symbols, that’s 𝑊 is equal to 𝐹𝑥. Now since we’re trying to work out what the force is, we need to rearrange this equation so we can isolate the force on the right-hand side of the equation.
We can do this by dividing both sides of the equation by 𝑥. The 𝑥s on the right-hand side cancel, leaving us with 𝑊 over 𝑥 is equal to 𝐹. All that remains now is for us to substitute in our values and find out the value of the force.
And the force is equal to 0.75, which is the work done, divided by 0.30, which is the distance moved. And that fraction simplifies to 2.5. But we also need to remember to put in the units. The units of force are newtons. Therefore, our final answer is that the force applied is 2.5 newtons.
