Define mechanical advantage in a simple machine.

• A. The ratio of output force to input force; how many times the input force is multiplied.
• B. The ratio of input work to output work.
• C. The speed increase provided by a machine.
• D. The efficiency of a machine.

Answer: (A)

Mechanical advantage is how much a simple machine increases your effort, i.e., the ratio of the force the machine outputs to the force you input. In other words, it tells how many times your input force is multiplied by the machine. For example, if you push with 10 newtons and the machine lifts or moves 50 newtons, the mechanical advantage is 5. This shows why devices like levers and pulleys feel easier to use: you trade a smaller force for a larger output force. The other ideas describe energy transfer, speed changes, or overall efficiency, which aren’t about how much the force is multiplied.