P5

Question 1

Which waves don’t need a medium (matter) to travel through?

Answer 1

Electromagnetic waves

Question 2

Define amplitude.

Answer 2

The amplitude of a wave if the displacement from the rest position to a crest or trough.
The distance from the middle to the crest or trough

Question 3

Define wavelength.

Answer 3

The wavelength is the full cycle of the wave eg. Crest to crest or from compression to compression on longitudinal waves.

Question 4

Define frequency

Answer 4

Frequency is the number of complete waves or cycles passing a certain point per second.
Frequency is the number of waves or oscillations per second.

Question 5

Define time period

Answer 5

The number of second it takes for one full cycle.

Question 6

What direction are the vibrations in a transverse wave?

Answer 6

In transverse waves, the vibrations are perpendicular (at 90 degrees) to the direction the wave travels.

Question 7

Examples of transverse waves

Answer 7

All electromagnetic waves
S waves
Ripples and waves in the water

Question 8

What direction is energy transferred in transverse waves?

Answer 8

Energy is transferred horizontally

Question 9

What direction are the vibrations in longitudinal waves?

Answer 9

In longitudinal waves, the vibrations are parallel to the direction the wave travels.

Question 10

Examples of longitudinal waves

Answer 10

Sound waves

P waves

Question 11

What direction is energy transferred in longitudinal waves?

Answer 11

Horizontally

Question 12

What does a time trace show?

Answer 12

A time trace shows how displacement varies with time at a particular position.

Question 13

What does a snapshot show?

Answer 13

A snapshot of a wave shows how displacement varies with distance at a particular time.

Question 14

Similarities and differences between a time trace and a snapshot.

Answer 14

Differences:
In the time trace you can measure the period from any point on a wave to the same point on the next wave.
On the snapshot you can measure wavelength from any point on the wave to the same point on the next wave.

Similarities:
On either diagrams you can measure wavelength from the middle to the top or bottom (trough) of a wave.

Question 15

What is the equation to work out wave speed?

Answer 15

Wave speed (m/s) = frequency (Hz) x wavelength (m)

Question 16

How can you model transverse waves?

Answer 16

You can use ripples on water waves to model transverse waves.
The surface of the wave moves up and dos. As the wave moves through the water. You can see that by putting a small cork on the surface. The wave travels but the water doesn’t.
This is the same for sound waves. The waves move away from your mouth but the air does not.