defining waves

Question 1

what is a longitudinal wave

Answer 1

where the wave propagation is in the same direction as the particle oscillation

Question 2

what is a transverse wave

Answer 2

where the wave propagation is perpendicular to the particle oscillation

Question 3

when are two waves completely out of phase?

Answer 3

at 180 degrees or pi radians

Question 4

what is path difference?

Answer 4

the difference in distance travelled by two waves going from the same starting point to the same ending point.

Question 5

what are the two polarisations?

Answer 5

vertical and horizontal

Question 6

if all of a light source has one polarisation (all vertical or horizontal) what happens

Answer 6

it becomes polarised light