Final answer:
Amy does 200 joules of work by using a force of 20 N to push the lawn mower 10 meters, according to the formula W = Fd.
Step-by-step explanation:
The student's question involves calculating the amount of work done when pushing an object across a distance. The formula to calculate work in physics is given as W = Fd, where W represents work, F is the force applied in newtons, and d is the distance in meters over which the force is applied.
Given that Amy uses 20 N of force to push a lawn mower 10 meters, we can apply the formula to find the work done. Substituting the given values, we get:
W = Fd = (20 N)(10 m) = 200 N·m
In physics, 1 N·m is equivalent to 1 joule (J), thus Amy does 200 joules of work when pushing the lawn mower.