Summary Notes - Topic 3 Waves - Edexcel Physics IG_241205_173300

Transverse waves

Waves with peaks and troughs, where vibrations are at right angles to the direction of travel.

Longitudinal waves

Waves consisting of compressions and rarefactions, with vibrations in the same direction as the direction of travel.

Amplitude

The distance from the equilibrium position to the maximum displacement of a wave.

Wavefront

A line joining points on a wave at the same point in their wave cycle at a given time.

Frequency

The number of waves that pass a single point per second.

Wavelength

The distance between a point on one wave and the same point on the next wave.

Time period

The time taken for one complete wave to pass a fixed point.

Speed of a wave

The product of its frequency and wavelength; v = fλ.

Doppler Effect

The change in observed frequency and wavelength due to the motion of a wave source relative to an observer.

Law of reflection

States that the angle of incidence equals the angle of reflection.

Refraction

The changing of wave speed when a wave enters a new medium.

Electromagnetic spectrum

The range of all types of electromagnetic radiation ordered by wavelength and frequency.

Radio waves

Used for radio and television communications, having long wavelengths and being reflected by the ionosphere.

Microwaves

Used in satellite transmissions and cooking, with a greater frequency and the ability to penetrate through materials.

Infrared radiation

Used in heaters and night vision equipment.

Visible light

Used in fibre optics and photography, part of the electromagnetic spectrum.

Ultraviolet light

Used in fluorescent lamps, with exposure risks including skin cancer.

X-rays

High-frequency waves used in medical imaging that can penetrate materials easily.

Gamma radiation

Used for sterilising food and medical equipment due to its high energy.

Microwave hazards

Can cause internal heating of body tissues.

Infrared hazards

Can cause skin burns.

Ultraviolet hazards

Increases the risk of skin cancer and blindness.

X-ray and Gamma ray hazards

Ionising radiation that can cause mutations leading to cancer.

Protective shielding

Dense materials like lead used to minimize exposure to X-rays and Gamma rays.

Vibration in transverse waves

Occurs at right angles to the direction of wave travel.

Vibration in longitudinal waves

Occurs in the same direction as the wave travel.

Compression

When particles are pushed together in a longitudinal wave.

Rarefaction

When particles are moved apart in a longitudinal wave.