Topic P5 - Waves in Matter

Question 1

Definition of waves:

Answer 1

Waves transfer energy from one place to another without transferring any matter.

Question 2

What direction do waves transfer energy in?

Answer 2

The direction they are travelling in.

Question 3

What happens when waves travel through a medium?

Answer 3

The particles of the medium vibrate and transfer energy between each other but overall, the particles stay in the same place.

Question 4

Definition of amplitude:

Answer 4

The displacement from the rest position to a crest or trough.

Question 5

Definition of wavelength:

Answer 5

The length of a full cycle of the wave, e.g. from crest to crest (or from compression to compresstion).

Question 6

Definition of frequency:

Answer 6

The number of complete waves or cycles passing a certain point per second.

Question 7

What is frequency measured in?

Answer 7

hertz (Hz)

Question 8

1Hz =

Answer 8

1 wave per second =

Question 9

Definition of transverse waves:

Answer 9

The vibrations are perpendicular to the direction the wave travels in.

Question 10

Examples of transverse waves:

Answer 10

1) All electromagnetic waves, e.g. light
2) S waves
3) Ripples and waves in water

Question 11

How would you use a spring to show a transverse wave?

Answer 11

Wiggle the spring up and down.

Question 12

Can transverse waves travel through liquids?

Answer 12

They can travel on the surface of a liquid, but they can’t travel through liquids.

Question 13

Definition of longitudinal waves:

Answer 13

The vibrations are parallel to the direction the wave travels.

Question 14

Examples of longitudinal waves:

Answer 14

Sound waves and P waves.

Question 15

What happens when longitudinal waves pass through a medium?

Answer 15

They squash up and stretch out the arrangement of particles in the medium they pass through making compressions (high pressure, lots of particles) and rarefractions (low pressure, fewer particles).

Question 16

How would you use a spring to show longitudinal waves?

Answer 16

Push the end of a spring.

Question 17

wave speed (m/s) =

Answer 17

frequency (Hz) x wavelength (m) =

Question 18

1KHz =

Answer 18

1000 Hz =

Question 19

1MHz =

Answer 19

1000000 Hz =

Question 20

What do you use to measure the speed of sound?

Answer 20

An Oscilloscope.

Question 21

What equipment it needed to find the speed of sound?

Answer 21

• signal generator
• speaker
• two microphones
• oscilloscope

Question 22

Method for the speed of sound experiment?

Answer 22

• Set up oscilloscope so detected waves at each microphone are shown as separate waves.
• Start with both microphones together then move one away until the waves are aligned
• Measure the distance between the microphones to find one wavelength
• you can then use the equation and sub in the wavelength and frequency from the signal generator