Standing Wave 2

Question 1

what happens when a transverse wave pulse reaches an end that is free to move

Answer 1

the reflected wave is not reflected

as there is no fixed end, there is nothing to apply a downward force to the wave so it maintains its upwards displacement.

Question 2

how is a sound wave relfected against fixed surface

Answer 2

when a compresion meets a fixed surface, particle push aginst the surface and the surface pushes against the particles due to 3rd law and sends a compression back in the opposite direction

Question 3

difference between transverse and lognitudinal waves in reflections

Answer 3

longitudinal hittin a fixed surface is like a transverse hitting a free boundary

longitudinal hittin an open end is like transverse hitting a fixed boundary

Question 4

what happens when a compression reaches an open end

Answer 4

diffracts outwards, pulling more air out of the pipe with it

the rest of the air in the pipe moves up to take the place of this missing air and causes a refraction to travel in the opposite direction

Question 5

what happens if a rarefaction reaches an open endh

Answer 5

higher pressure air outside the pipe rushes in and sends a compression in original direction

Question 6

standing waves in open pipes

Answer 6

open ends are always pressure nodes and displacement antinodes

2l/n

pressure is n = number of antinodes
displaement is n = number of nodes

Question 7

standing waves in closed open pipes

Answer 7

4l/2n-1

closed end of the pipe is always displacement node and pressure antinode

n is number of antinodes