Sarah uses an inclined plant to load a chest into her truck. If she does 84 Joules of work, and the inclined plane is 3 meters long, how much force does she expend?

The force Sarah expends is 28 Newtons. This can be calculated by dividing the work (84 Joules) by the length of the inclined plane (3 meters): 84 Joules / 3 meters = 28 Newtons.

To find the force expended by Sarah, we can use the formula for work:

Work = Force x Distance

Rearranging the formula, we have:

Force = Work / Distance

Given that Sarah does 84 Joules of work and the inclined plane is 3 meters long, we can substitute these values into the formula to find the force:

Force = 84 Joules / 3 meters

Calculating this, we get:

Force = 28 Joules/meter

Therefore, Sarah expends a force of 28 Joules/meter to load the chest into her truck using the inclined plane.