A machine is a device that helps make our work easier. Machines don’t change the amount of work needed to do a job, but they can change the size, direction or amount of the force doing the work. They can also change the kind of friction two objects are creating. This change, called mechanical advantage, redirects the force in a way to make the work easier for us. Simple machines include levers, inclined planes, wedges, screws and wheels and axles—all of them help us out by changing the direction, amount or speed of force or the distance needed to do work.

Question

According to the passage, which of the following is an example of a simple machine that makes our work easier?

A
a lawnmower used to cut the grass

B
a laptop computer that fits easily in a backpack

C
a pulley that lifts an elevator off the ground

D
a remote control for the television

Answer 1

According to the passage, an example of a simple machine that makes our work easier is:

C a pulley that lifts an elevator off the ground.

A pulley is considered a simple machine, as it helps change the direction of the force needed to lift an object, making work easier.