2.4 nature of waves

Question 1

progressive wave

Answer 1

A pattern of disturbances travelling through a medium and carrying energy with it.
involving the particles of the medium oscillating about their
equilibrium positions

OR

A travelling pattern of
oscillating electric and magnetic fields carrying energy with it

Question 2

longitudinal wave

Answer 2

a wave in which the oscillations of the particles is parallel to the direction of energy transfer.
there are rarefaction and compression

Question 3

transverse wave

Answer 3

waves where the particle oscillations are perpendicular to the direction of energy transfer.
e.g. electromagnetic waves

Question 4

what does polarising filters do

Answer 4

only allow oscillations in one plane to pass through

Question 5

how is polarisation used as evidence of the nature of transverse waves

Answer 5

can only occur if a waves oscillations are perpendicular to its direction of travel (as they are in transverse waves)

Question 6

phase

Answer 6

the position of a certain point on a wave cycle

Question 7

frequency

Answer 7

number of waves passing through a point per second

Question 8

wavelength

Answer 8

displacement between two adjacent peaks on a wave

Question 9

amplitude

Answer 9

maximum displacement of the wave from its equilibrium position

Question 10

wave fronts

Answer 10

the lines of constant phase. all positions on the wave are in phase. the wave fronts travel radially from a source and therefore he direction of travel of the waves are along a radial direction