Waves Y9

Question 1

What substances can S and P waves travel through?

Answer 1

S waves can travel through Solids.
P waves can travel through Liquids and Solids.

Question 2

What equation relates to wave speed, frequency and wavelength

Answer 2

v = f x ʎ

Question 3

How is ultrasound used in sonar?

Answer 3

A pulse of ultrasound is emitted and the time taken for it to reflect and be detected is recorded. This is used to calculate distances.

Question 4

Explain how a change in wave speed can cause refraction

Answer 4

When part of a wavefront enters a medium before the rest, It’s speed will change first. This will cause the wavefront to move towards or away from the normal.

Question 5

What are some effects of the refraction of light?

Answer 5

Some objects are observed to be in a different place to where they actually are (fish underwater).

Question 6

What do waves transfer?

Answer 6

Waves transfer energy and information but not matter.

Question 7

How are sound waves in air converted to vibrations in solids?

Answer 7

Sound waves cause changes in pressure on the surface of a solid, causing particles in the solid to vibrate.

Question 8

What are the differences between longitudinal and transverse waves?

Answer 8

Longitudinal waves: Vibrations are parallel to the direction of energy transfer.
Transverse waves: Vibrations are perpendicular to the direction of energy transfer.

Question 9

What is refraction?

Answer 9

The changing direction of light as it enters a different medium.

Question 10

Define the terms frequency, wavelength, amplitude, period and velocity.

Answer 10

Frequency: How many full wavelengths pass a point each second.
Wavelength: The distance between 2 identical points along a wave.
Amplitude: The distance between the equilibrium position and the peak of a wave.
Period: The time taken for one complete wavelength to pass a point
Velocity: Distance moved by a wave per unit time.

Question 11

What is the name of this ray?

Answer 11

The emergent ray