Physics Y10

Wave

A disturbance that transfers energy from place to place through a medium. Temporiarly displacing those particles in a medium but they then go back to their rest positions.

Pulse

A single disturbance moving through a medium from one location to another.

Medium

A material which a wave travels through.

What does a Wave carry

energy but not matter.

Transverse wave

A wave that moves the medium in a direction perpendicular to the direction in which the wave travels. Still is a wave with amplitude, frequency and wavelength.

Longitudinal waves

a wave in which the particles of the medium vibrate parallel to the direction of the wave. Still is a wave with amplitude, frequency and wavelength.

ElectroMagnetic wave

a wave that consists of oscillating electric and magnetic fields, which radiate outward at the speed of light. Does not need a medium to travel always travels the same speed.

Mechanical wave

A wave that requires a medium through which to travel and are far slower than electromagnetic waves.

Crest

the highest point of a wave

Through

Lowest point of a wave

Compression

The part of a wave where the particles of the medium are close together.

Rarefaction

The part of a wave where the particles of the medium are far apart

amplitude

For a wave or vibration, the maximum displacement on either side of the equilibrium (midpoint) position.

Wave cycle

one complete motion of the repeating pattern of a wave

Wave Formula

Velocity= frequency times wavelength

Frequency formula

1/period

wave length

Horizontal distance between the crests or between the troughs of two adjacent waves

wave period

the time required for one cycle

hertz

the unit of frequency, equal to one cycle per second

Interference

result of the combination of two or more waves of the same type and frequency in which the amplitude of the resulting wave is equal to the sum of the amplitudes of the combining waves

Constructive

Increase of amplitude in interference

Destructive

Decrease of amplitude in interference

principle of superposition

When two or more waves overlap the resulting displacement is the result of algebraicly sum of their individual disturbances.

Disturbance

Refers to any change from the equilibrium state that travels through the medium, carrying energy without permanently displacing the medium itself. It can be a variation in pressure, density, or displacement of particles in the medium.

Angle of incidence

The angle of incidence is the angle between the incident ray and the normal to a a surface

Angle of reflection

From the angle of normal in a surface and the reflection ray

Incident ray

An incident ray is a ray of light that strikes a surface. It is the incoming ray before it undergoes reflection, refraction, or absorption.

Refraction

Bending of light as it passes from one medium to another, caused by a change in its speed. this can be observed in glass as light is a bit slower in glass.

Normal

90 degree angle form the medium

Reflected ray

A reflected ray is the light ray that bounces off a surface, obeying the law of reflection, where the angle of incidence equals the angle of reflection.

Laws of reflection

• the angle of incidence is equal to the angle of reflection

• All lie on the same plane.

Snell Laws

N1 sin (beta)1=n2 sin (beta)

Index of refraction

1.0 for air which is same for vacuum. For different transparent materials it’s different meaning light can go at different speeds. To know what speed you divide it by the vacuum speed of light

speed of sound

341 +0.6 x Celsius

Resonant frequency

Natural frequency where the medium vibrates at the highest amplitude