Waves

AQA Physics for Section 2 - Waves & Optics

What is a wave? What is an electromagnetic wave?

• A transfer of energy without transfer of matter

• A wave made of oscillating electric and magnetic fields that can travel through a vacuum

What is a mechanical wave?

A wave that requires a medium (particles to travel through)

How do mechanical waves transfer energy through a medium?

Particles vibrate and pass energy to neighbouring particles

What is displacement of a vibrating particle?

It’s distance and direction from its equilibrium position

What is amplitude?

The maximum displacement of a vibrating particle from equilibrium

What is wavelength?

The distance between two particles on a wave that are in-phase

What is the period of a wave?

The time taken for one complete oscillation

What is frequency?

The number of complete oscillations per second (Hz)

What is phase? What is phase difference?

• The fraction of a cycle completed by a vibrating particle

• The difference in the fraction of a cycle between two vibrating particles

What is an oscilloscope used for?

To measure wave voltage, period, and frequency using a trace

What is the phase difference in radians formula?

phase difference_{(in radians)} = ^2πd/_λ