Waves

Waves

Their characteristics, types and how they interact with each other

Waves is a disturbance

• It transfers energy from one place to another

• It does not transfer mass. The particle in the wave is not moving

Example of how wave looks like

How to draw waves as graph

Wave can be drawn two ways, the first is displacement distance, and another is displacement time. See the x-axis on both graph

Characteristics of Waves

• Amplitude

• Wavelength

• Period

• Frequency

• Velocity

Amplitude (A)

• Represented by the letter a and e

• It is the maximum displacement where graph cannot go higher or lower

• It's must be measured as length, so the SI unit is m (meter)

Wavelength (λ) -Pronounced Lambda

• Represented by letter b

• Must be measured on displacement distance graph,

• This is because distance is x axis which measures length, so the SI unit is m (meter)

• Is the length between two same phase cycle (amplitude to amplitude or similar)

Period (T)

• Represented by letter c

• Time taken for one wavelength to happen

• Need to measure on displacement time graph, SI unit is s (seconds)

• Is time taken for one wavelength takes place

Frequency (f)

• Represented by letter c

• Is the number of waves (wavelength) that happens in one second.

• Need to be calculated using formula

• f=1/T and the unit is Hz (Hertz)

Velocity (v)

• Represented by letter y

• Is the distance traveled by the waves over specific time

• Need to be calculated using formula

• v = f(λ) and SI unit is ms^-1

Wave phenomena

Changing of wave characteristics due to external factors

Damping

• Represented by graph a

• Happens when amplitude of wave becomes smaller and smaller

• This is because of internal friction between molecules of external friction between objects

• The friction causes heat energy which makes the wave loses energy

Resonance

• Represented by graph b

• Happens when amplitude of wave becomes bigger and bigger

• All objects have natural frequency which vibrates by itself.

• If we add vibration of same frequency, the wave will increase in amplitude

• Example is glass breaking when directed to singer voice

Reflection of Waves

Changing of direction of waves when directed towards obstacle. It follows the law of reflection (incidence angle = reflected angle)

5 Components of Reflection

• Incidence wave a (on solid surface)

• Normal line f (90°) from surface at point of incidence

• Incidence angle d, measured from normal line to incidence ray

• Reflected angle e

• Reflected wave b