Amplitude (A)

Definition

Amplitude (A) is the maximum displacement of an oscillating object from its equilibrium position. It measures the extent of oscillation and is a key parameter in describing wave motion.

5 Must Know Facts For Your Next Test

1. Amplitude is directly proportional to the energy of the oscillation; higher amplitude means more energy.
2. In simple harmonic motion, amplitude remains constant if no damping forces are present.
3. Amplitude does not affect the period or frequency of an oscillation.
4. The unit of amplitude depends on what is being measured, such as meters for displacement or volts for voltage signals.
5. $A$ can be found using the formula $A = \sqrt{x_{max}^2 - x_{min}^2}/2$, where $x_{max}$ and $x_{min}$ are the maximum and minimum displacements.

Review Questions

• How does amplitude relate to the energy in an oscillating system?
• What happens to the amplitude in simple harmonic motion if there are no damping forces?
• Does changing amplitude affect the period or frequency of an oscillation?

Related terms

Frequency:

The number of complete oscillations made by an object in one second, typically measured in Hertz (Hz).

Period:

The time taken for one complete cycle of an oscillation, usually measured in seconds.

Phase:

A measure of the position within a cycle of an oscillation at any given time, often expressed in degrees or radians.