11: Wave Motion

Question 1

Progressive wave

Answer 1

A progressive wave is a wave in which energy is carried from one point to another by means of vibrations or oscillations within the wave. Particles are not transported along the wave.

Question 2

Transverse wave

Answer 2

The plane of oscillations of particles is at right angles to the direction of transfer of the energy of the wave.

• can be polarized

Question 3

Longitudinal wave

Answer 3

The plane of oscillations of particles in the wave are in the same direction as the transfer of the energy of the wave.

Question 4

Malus’s Law

Answer 4

Malus’s Law states that the intensity of a beam of plane-polarized light after passing through a rotatable polarizer is directly proportional to the square of the cosine of the angle through which the polarizer is rotated from the position that gives the maximum intensity.

Question 5

Malus’s Law equation

Answer 5

I = I₀ cos²θ

I ∝ cos²θ