National 5 Physics - Unit 1

What all Waves are produced by

A vibrating object

Wave Direction

Direction of energy travel

A Low Amplitude Wave

A Small Wave

A High Amplitude Wave

A Big Wave

What Waves transfer

Energy

Transverse Waves

Waves where the particles of the medium oscillate at perpendicular to the direction of the Wave itself

Longitudinal Waves

Waves where the particles of the medium oscillate parallel to the direction of the Wave itself

An example of a Transverse Wave

Water Waves

Wavelength

The distance between any two adjacent crests or troughs, measured in meters (m)

Amplitude

The distance between the Line of Zero Disturbance and the top of a crest or bottom of a trough

Frequency

The number of whole waves made in one second, measured in Hertz (Hz)

f=N/t

Where f = wave frequency, N = number of waves produced or passing a point and t,= time taken to produce the waves or for the waves to pass the point

Adjacent

Right next to each other

Period T

The time taken to produce one whole wave or the time taken for one whole wave to pass a point, measured in seconds (s)

T=1/f or f=1/T

T = Period T and f = frequency

d=vxt

Where d = distance travelled by wave (m), v = wave speed (ms-1) and t = time taken to travel (s)

v=fλ

Where v = wave speed (ms-1), f = frequency of wave (Hz) and λ = wavelength of wave (m)

The quoted value for the Speed of Sound in Air

Vₛ=340ms-1

Diffraction

The curving of a wave around a barrier or through a gap

Longer Wavelengths

They Diffract more, gap width ≤ 1λ

Shorter Wavelengths

They Diffract Less, gap width > 1λ

Source of Radio Waves

Stars, Radio Transmitters

Detector of Radio Waves

Aerials

Use of Radio Waves

Communication

Sources of Microwaves

Mobile devices, microwave ovens

Detectors of Microwaves

Aerials, Satellite dishes

Uses of Microwaves

Communication, Cooking

Sources of Infrared Waves

Hot objects (e.g. sun), IR laser

Detectors of Infrared Waves

Thermometers, Thermistors

Use of Infrared Waves

Remote controls

Sources of Visible Light

Stars, Light bulbs, LEDs, Lasers

Detectors of Visible Light

Retina of the eye, Photographic film, Charge-Coupled Device (CCD)

Use of Visible Light

Seeing

Sources of Ultra Violet Waves

Very hot objects, Mercury vapour lamps

Detector of Ultra Violet Waves

Photographic film

Use of Ultra Violet Waves

Setting fillings in teeth

Sources of X-Rays

X-Ray tubes, Very bright stars

Detectors of X-Rays

Photographic film, Transistor arrays

Use of X-Rays

Medical and Security scanning

Source of Gamma Rays

Radioactive nuclei

Detector of Gamma Rays

Geiger-Muller tube

Uses of Gamma Rays

Radiotherapy, Medical scanning

Radio Waves

The EM Wave with the longest wavelength and lowest frequency that diffracts the most

Gamma Rays

The EM Wave with the shortest wave length and highest frequency that diffracts the least

3x10⁸ms-1

The speed of all EM Waves in air or a vacuum

400nm-700nm

The range of EM Wave lengths the human eye is sensitive to

Refraction

The change in speed when a wave travels from one medium into another

Angle of Incidence

The angle between the Incident Ray and Normal before refraction

Angle of Refraction

The angle between the Incident Ray and the Normal after refraction

The EM Spectrum in order of wavelength

Radio Waves, Microwaves, Infrared, Visible Light, Ultraviolet Waves, X-Rays, Gamma Waves