Mechanical advantage

Definition

Mechanical advantage is the ratio of the output force produced by a machine to the input force applied. It quantifies how much a simple machine multiplies the input force.

5 Must Know Facts For Your Next Test

1. Mechanical advantage (MA) can be calculated using MA = \frac{F_{out}}{F_{in}}, where $F_{out}$ is the output force and $F_{in}$ is the input force.
2. In an ideal (frictionless) machine, mechanical advantage also equals the ratio of input distance to output distance: MA = \frac{d_{in}}{d_{out}}.
3. Simple machines such as levers, pulleys, and inclined planes are designed to provide mechanical advantage.
4. The efficiency of a machine is related to its mechanical advantage and can be less than 100\% due to energy losses like friction.
5. A higher mechanical advantage means less input force is needed to perform the same amount of work.

Review Questions

• How do you calculate mechanical advantage using input and output forces?
• Why does actual mechanical advantage differ from ideal mechanical advantage?
• What simple machines are commonly used to achieve mechanical advantage?

Related terms

Lever: A rigid bar that pivots about a fulcrum point to multiply force.

Pulley:

A wheel on an axle designed to support movement and change direction of a taut cable; used to lift loads.

Efficiency:

\text Efficiency is defined as \frac{Work Output}{Work Input} \times 100\%, representing how well a machine converts input energy into useful output work.