Science T2

Classification of Waves

Transverse Wave

Longitudinal Wave

  • Travel perpendicularly to the direction of the material the wave moves through.

Example : Moving a rope.

  • Travels in a parallel way to the direction of the material that the wave moves through.

Example : Moving a slinky.

Mechanical Wave VS Electromagnetic Wave

Mechanical Waves :


  • Need a medium to travel through.
  • Can't travel through a vacuum.

Examples =

  • Sound waves
  • Water waves
  • Earthquake wave travelling in Earth.

Characteristic of Wave :

Wavelength

Speed

Wave cycle

Amplitude

Period

Frequency

Definition : Period is the amount of time a wave takes to finish one cycle


How to find it?
There are 2 formulas we can use, first is...

  1. Time/Number of Waves (Time divided by number of waves)
    Second is...
  2. 1/Frequency (1 divided by the frequency of the wave)

Unit of Measurement :
Measured in "Seconds"

Definition : A wave's crest to crest or through to through.


How to find it?
We can find it by looking at how many crest to crest or through to through there are in the whole wave.

Definition : The distance between a a crest to crest or through to through (Distance in a wave cycle)


How to find it?
There are 2 ways we can use to find wavelength, first is...

  1. Speed/Frequency (Wave speed divided by the frequency of the wave).
    Second is...
  2. Looking at the meter written in a diagram

Unit of Measurement :
Measured in "Meters".

Electromagentic!

Electromagnetic Waves :


  • Can travel through a medium.
  • Can travel through a vacuum.
    (Basically can travel through both).

Examples :

  • Visible Light
  • Ultraviolet

Spectrum of Light :
image


Important things to know about it :

  • Visible Light is the only electromagnetic wave us humans can see.
  • The lower a wave is on the spectrum of light, the lower the frequency (Meaning radio waves have the lowest frequency and gamma rays have the highest).
  • The higher the wave the lesser the wavelength of it (Meaning radio waves have the biggest wavelength and gamma rays have the least).

Definition : The distance of a wave from it's resting position and it's crest or through.


How to find it?
We can find it by looking at the meter written in the diagram usually shown in a question.


Unit of measurement : In "Meters"

Definition : The frequency of a wave is the number of waves that pass a point in a certain period of time.


How to find it?
There are 3 ways we can find it, first is...

  1. Number of waves/time (Number of waves divided by the time).
    Second is...
  2. Speed/Wavelength (Speed of the wave divided by it's wavelength).
    Third is...
  3. 1/Period (1 divided by period of the wave).

Definition : Speed is the total distance covered by the wave in a given time period.


How to find it?
We can find it using a formula..

  1. Wavelength x Frequency (Wavelength multiplied by Frequency)

image