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Measuring Waves!

• Displacement: X, m. A vector therefore has direction and magnitude.
• How far a point on the wave has moved form its undisturbed position.
• Amplitude, A, m, No direction, only magnitude.
• Maximum magnitude of the displacement, i.e the distance from the undisturbed position to the crest, or trough.
• Displacement has magnitude and direction bcz is a vector.
• -How far a point on the wave moves from its undisturbed position.
• Amplitude-A, only has magnitude.
• -The maximum magnitude of the displacemen

Slide 2

• Phase- A measurement of the position of a certain point along the wave cycle. - USED TO DESCRIBE THE LOCATION WITHIN A SINGLE WAVELENGTH.
• Phase Difference-
• The amount by which one wave lags behind another wave.
• The difference between 2 identical points at max displacement on 2 waves.

Slide 3

• Transverse, Longitudinal waves
• TRANSVERSE WAVES- Displacement of vibrations are perpendicular to the direction of energy transfer.
• All EM waves=Transverse, travel as: vibrations (perp to direct of E transfer) through mag and elec fields.
• Examples: RIPPLES ON WATER, waves on strings, S waves.
• Transverse waves- Displacement of vibrations= perpendicular to direction of energy transfer .
• All EM waves=-transverse, travel as vibrations, through magnetic and electric fields.
• Examples: Ripples on water, S waves, waves on strings.

Slide 4

• LONGITUDINAL WAVES
• Displacement of vibrations= parallel to direction of energy transfer.
• E.g.'s: SOUND, Seismic P-WAVES
• Longitudinal waves
• Displacement of vibrations is parallel to direction of energy transfer.
• Examples SOuND WAVES SEISMIC P-WAVES.
• Sound waves consist of alternate compressions and rarefactions of the medium its traveling through. THEREFORE why sound cannot travel in a vacuum.

POLARISED WAVES!

• -Ordinary light waves are a mixture of different directions of vibrations.
• -A POLARIZING FILTER can be used to polarize light and other waves.
• -It only transmits vibrations in one direction.
• -If you have 2 polarizing filters at right angles, to each other, then no light will get through.