Sound and Light

Question 1

What is a wave?

Answer 1

A wave is an oscillation or a vibration that transfers energy or information.

Question 2

What are the three important features of a wave?

Answer 2

Amplitude, wavelength, and frequency.

Question 3

What is amplitude?

Answer 3

Amplitude is the distance from the middle to the top of the wave.

Question 4

What is wavelength?

Answer 4

Wavelength is the distance from one point to another point on another wave at the same place.

Question 5

What is frequency?

Answer 5

Frequency is the number of waves that pass a particular point in one second.

Question 6

What are the two types of waves?

Answer 6

Longitudinal and transverse.

Question 7

What are rarefactions?

Answer 7

Rarefactions occur when the wavelength is larger.

Question 8

What are compressions?

Answer 8

Compressions occur when the wavelength is smaller.

Question 9

What is reflection in terms of waves?

Answer 9

Reflection is when a wave bounces off surfaces and barriers.

Question 10

What is superposition?

Answer 10

Superposition is when two waves are put together, either adding up or canceling out.

Question 11

What happens when two waves are in step?

Answer 11

They will add up, resulting in more height.

Question 12

What happens when two waves are not in step?

Answer 12

They will cancel out, resulting in less height.

Question 13

What are sound waves?

Answer 13

Sound waves are vibrations.

Question 14

What is a medium?

Answer 14

A medium is either a solid, liquid, or gas.

Question 15

How does the speed of sound vary in different media?

Answer 15

The speed of sound is fastest in solids, then liquids, and finally gases.

Question 16

Why is light faster than sound?

Answer 16

Light is faster than sound because light waves do not need a medium to travel through.

Question 17

What is an oscilloscope used for?

Answer 17

An oscilloscope is used to visualize sound waves through a microphone.

Question 18

How is volume measured?

Answer 18

Volume is measured in decibels (dB).

Question 19

What is the relationship between dB and sound intensity?

Answer 19

Each increase of 10 dB increases the intensity of the sound by 10x.

Question 20

What determines the pitch of a note?

Answer 20

The pitch of a note depends on the frequency.

Question 21

How does frequency relate to pitch?

Answer 21

High pitched sounds have a higher frequency, while low pitched sounds have a lower frequency.

Question 22

How is frequency measured?

Answer 22

Frequency is measured in hertz (Hz).

Question 23

What happens to the frequency to create a higher pitched sound?

Answer 23

To create a higher pitched sound, something must vibrate faster.

Question 24

Does changing the frequency affect the amplitude?

Answer 24

Changing the frequency of the wave does not affect the amplitude.

Question 25

What is the pinna?

Answer 25

The pinna is the part of the ear that we can see.

Question 26

What happens as fluid moves in the cochlea?

Answer 26

As the fluid in the cochlea moves, the hairs inside also move.

Question 27

What do specialized cells at the base of the hairs do?

Answer 27

They convert movement into electrical signals.

Question 28

What is the human audible range?

Answer 28

The human audible range is 20-20,000 Hz.

Question 29

What are frequencies below 20 Hz called?

Answer 29

Frequencies below 20 Hz are called infrasound.

Question 30

What are frequencies above 20,000 Hz called?

Answer 30

Frequencies above 20,000 Hz are called ultrasound.

Question 31

What is an echo?

Answer 31

An echo is produced when a sound is reflected off a surface.

Question 32

What does the time delay of an echo depend on?

Answer 32

The time delay depends on the distance.

Question 33

What emits light?

Answer 33

A source of light emits light.

Question 34

What happens to light when it reflects off surfaces?

Answer 34

The light reflects off many surfaces and gets absorbed into our eye.

Question 35

What are luminous objects?

Answer 35

Objects that give out light are called luminous objects.

Question 36

What are non-luminous objects?

Answer 36

Most objects that we look at are non-luminous, meaning they do not give off light.

Question 37

What does transparent mean?

Answer 37

Transparent means that the object is fully see-through.

Question 38

What does translucent mean?

Answer 38

Translucent means that the object is partially see-through.

Question 39

What does opaque mean?

Answer 39

Opaque means that the object is not see-through at all.

Question 40

What can light travel through?

Answer 40

Light can travel through gases, some liquids, but not solids.

Question 41

What is a vacuum?

Answer 41

A vacuum is a completely empty space through which light can travel.

Question 42

How fast does light travel?

Answer 42

Light travels at a speed of about 300,000,000 m/s.

Question 43

How much slower is sound compared to light?

Answer 43

Sound is about 1 million times slower than light.

Question 44

What is a light minute?

Answer 44

A light minute is the distance that light travels in 1 minute.

Question 45

What is a light year?

Answer 45

A light year is the distance that light travels in 1 year.

Question 46

What is the normal in relation to mirrors?

Answer 46

The normal is an imaginary line at 90° of the mirror.

Question 47

What is the incident ray?

Answer 47

The incident ray is the light ray coming in.

Question 48

What is the reflected ray?

Answer 48

The reflected ray is the light ray being reflected.

Question 49

What is the angle of incidence?

Answer 49

The angle of incidence is the angle between the normal and the incident ray.

Question 50

What is the angle of reflection?

Answer 50

The angle of reflection is the angle between the normal and the reflected ray.

Question 51

What does the law of reflection state?

Answer 51

When light is reflected from a mirror, the angle of incidence is equal to the angle of reflection.

Question 52

What is a virtual image?

Answer 52

A virtual image is formed because light has not traveled to the eye.

Question 53

What is refraction?

Answer 53

Refraction is when one wave travels from one medium to another.

Question 54

What happens to images as they go through our eyes?

Answer 54

The image is inverted, but our brain sorts it the right way up.

Question 55

What are the two types of lenses?

Answer 55

Convex and converging.

Question 56

What are photoreceptors?

Answer 56

Photoreceptors are the cells on our retina that respond to light.

Question 57

What is white light made up of?

Answer 57

White light is made up of 7 different colors: red, orange, yellow, green, blue, indigo, and violet.

Question 58

What is dispersion?

Answer 58

Dispersion is when you use a prism to separate colors into a spectrum.

Question 59

Why does dispersion happen?

Answer 59

Dispersion happens because colors like violet have a higher frequency than colors like red.

Question 60

What are the three primary colors of light?

Answer 60

Red, green, and blue.

Question 61

What are secondary colors?

Answer 61

Secondary colors are created by mixing two primary colors: cyan, yellow, and magenta.

Question 62

What does a filter do?

Answer 62

A filter removes colors from white light and transmits the color of the filter.