Simple machines are basic tools that make work easier. They reduce the amount of energy needed for a task and multiply the force by cleverly applying the laws of physics. There are six types of simple machines: the lever, the pulley, the screw, the inclined plane, the wedge, and the wheel and axle.
Which of the following is not a simple machine: lever, pulley, screw, or wheel and axle?
What is the most common use of a screw?
Simple machines were first recognized by whom?