Waves

Question 1

What do waves do?

Answer 1

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

Question 2

What are waves used for?

Answer 2

Waves can be used to transfer energy and information in the direction they are travelling

Question 3

What happens when a waves travels through a medium?

Answer 3

The particles of the medium vibrate and transfer energy and information between each other.

Question 4

What is the amplitude of a wave?

Answer 4

It is the displacement from the rest position to a crest or trough.

Question 5

What is the wavelength?

Answer 5

The wavelength is the length of a full cycle of the wave.

Question 6

What is frequency?

Answer 6

The number of complete cycles of the wave passing a certain point per second.

Question 7

What is the period of a wave?

Answer 7

The number of seconds it takes for a full cycle.

Question 8

What is a transverse wave / what does it look like that makes it different?

Answer 8

The vibrations in transverse waves are perpendicular to the direction a wave travels.

Question 9

What are the vibrations like in a longitudinal wave?

Answer 9

The vibrations in a longitudinal wave are parallel to the direction the wave travels.

Question 10

What do longitudinal waves do when they pass through a medium?

Answer 10

They squash up and stretch out the arrangement of particles in the medium they pass through, which makes compressions and rarefactions.

Question 11

What is the equation for wave speed?

Answer 11

Wave speed= Frequency x Wavelength

Question 12

What is the equation for speed?

Answer 12

Speed= distance/time

Question 13

Name 2 things that can happen when a wave meets a boundary:

Answer 13

. The wave could be absorbed by the second material - the wave transfers energy to the material’s energy stores. Often, the energy is transferred to a thermal energy store, which leads to heating.
. The wave is transmitted through the second material - the wave carries on travelling through the new material. This often leads to refraction. Refraction can be used in communications aw well as in the lenses of glasses and cameras.
. The wave is reflected - this is where the incoming ray is neither absorbed nor transmitted, but instead is ‘sent back’ away from the second material.

Question 14

What happens when a wave crosses a boundary?

Answer 14

The wave changes speed.

Question 15

What happens if a wave hits a boundary at an angle?

Answer 15

The change of speed causes a change in direction, refraction.

Question 16

What is a ray?

Answer 16

A ray is a line showing the path a wave travels in.

Question 17

What does a ray diagram show?

Answer 17

Ray diagrams can be drawn to show how a light ray refracts at the boundary between two materials.

Question 18

What is the angle of incidence the same as?

Answer 18

The angle of incidence is the angle of reflection.

Question 19

What happens when a wave passes through a dense material toward a less dense substance?

Answer 19

The wave can experience total internal reflection. It is reflected back into the material.

Question 20

What are sound waves caused by?

Answer 20

They are caused by vibrating objects.

Question 21

How does a sound wave pass through a solid?

Answer 21

It causes the particles to vibrate.

Question 22

What are the 3 factors that determine the frequency of an object?

Answer 22

Size
Shape
Structure

Question 23

What turns vibrations into electrical signals?

Answer 23

The cochlea turns vibrations into electrical signals which get sent to your brain.

Question 24

What is an infrasound wave?

Answer 24

Infrasound waves are sound waves so low in frequency that we can’t hear them. They are below 20 hz.

Question 25

What is ultrasound?

Answer 25

Ultrasounds are sound waves beyond the range of human hearing. Above 20000 hz.