What is a simple machine?

• A. A device that stores energy.
• B. A machine that converts energy from one form to another.
• C. A device that reduces the amount of energy required to perform a task.
• D. A device that changes the size or direction of a force, such as a lever or inclined plane.

Answer: (D)

A simple machine is a device that helps us do work more easily by changing the size or direction of a force. By using a lever or an inclined plane, you can apply a smaller force over a longer distance or redirect the force to where the load needs to move, making the task easier. That’s why describing it as a device that changes the size or direction of a force fits best. The idea isn’t about storing energy or converting energy from one form to another, and energy isn’t magically reduced—work is still done, just with less effort due to the mechanical advantage.