Light and Sound

Question 1

What is a transverse wave?

Answer 1

A wave where the vibration of the particles is perpendicular to the direction of energy transfer.

Question 2

What is a longitudinal wave?

Answer 2

A wave where the vibration of the particles is parallel to the direction of energy transfer.

Question 3

What feature of the wave is shown on the diagram?

Answer 3

Amplitude.

Question 4

What is amplitude?

Answer 4

The maximum displacement of particles from their rest position.

Question 5

In a longitudinal wave, what are areas where the particles are pushed together called?

Answer 5

Compressions.

Question 6

What is a louder sound associated with?

Answer 6

A higher amplitude.

Question 7

What is a high-pitched sound associated with?

Answer 7

A higher frequency.

Question 8

Give an example of a longitudinal wave.

Answer 8

Sound waves.

Question 9

Give an example of a transverse wave.

Answer 9

Light waves.

Question 10

What is an object that gives off light known as?

Answer 10

A luminous object.

Question 11

How can we see non-luminous objects?

Answer 11

By the light they reflect.

Question 12

What is it called when light hits an object and ‘stops’?

Answer 12

Absorption.

Question 13

What is it called when light hits an object and bounces off?

Answer 13

Reflection.

Question 14

What is a transparent material?

Answer 14

A material that lets light through without scattering.

Question 15

What is an opaque material?

Answer 15

A material that does not let light pass through.

Question 16

What is a translucent object?

Answer 16

An object that scatters light as it passes through.

Question 17

What happens to the angle of incidence compared to the angle of reflection?

Answer 17

They are equal/the same.

Question 18

What happens when the angle of incidence is greater than the critical angle?

Answer 18

All the light will be reflected (total internal reflection).

Question 19

What is total internal reflection?

Answer 19

When all the light is reflected by a material.

Question 20

Give two examples of where total internal reflection is found in real-life applications.

Answer 20

Periscopes and fibre-optic communications.

Question 21

What is the name of the colored circle around the pupil?

Answer 21

Iris.

Question 22

What is the purpose of the lens in the eye?

Answer 22

To focus light onto the retina.

Question 23

What is the retina?

Answer 23

The light-sensitive layer at the back of the eye, made up of rods and cones.

Question 24

What is the purpose of the optic nerve?

Answer 24

To carry messages from the retina to the brain.

Question 25

What are the colors of the spectrum that make up white light?

Answer 25

Red, Orange, Yellow, Green, Blue, Indigo, Violet.

Question 26

What does the color of light depend on?

Answer 26

The frequency of the wave.

Question 27

Why do black objects appear black?

Answer 27

They absorb all colors of light and reflect none.

Question 28

When red and green light is combined, what color is formed?

Answer 28

Yellow.

Question 29

When red and blue light is combined, what color is formed?

Answer 29

Magenta.

Question 30

When blue and green light is combined, what color is formed?

Answer 30

Cyan.

Question 31

What formula can we use to calculate the speed of sound?

Answer 31

Speed = distance/time.

Question 32

Do sound waves travel fastest in solid, liquid, or gas?

Answer 32

Solid.

Question 33

Do light waves travel fastest through a solid, liquid, or gas?

Answer 33

Gas (light travels fastest through a vacuum).

Question 34

When calculating the speed of sound using an echo, what must you remember?

Answer 34

The echo travels to an object and back again, so you may need to double the distance or halve the time provided.

Question 35

What happens to the path of light when it enters a new substance?

Answer 35

It bends.

Question 36

What is dispersion?

Answer 36

When light enters a prism and splits into the colors of the spectrum.

Question 37

Why do we end up with an inverted image formed on our retina when we look at an object?

Answer 37

Because light is refracted by the cornea and lens in our eye.

Question 38

What three colors of light can our eyes detect?

Answer 38

Red, green, blue.

Question 39

What happens to a wave when it changes speed?

Answer 39

It bends.

Question 40

If a sound is becoming lower pitched, what is decreasing?

Answer 40

The frequency

Question 41

If a sound is becoming lower in volume, what is decreasing?

Answer 41

The amplitude