7K Waves

Question 1

How are sounds generated?

Answer 1

When particles vibrate.

Question 2

What type of wave is sound?

Answer 2

Longitudinal

Question 3

What can’t sounds travel through?

Answer 3

Empty space (a vacuum)

Question 4

In which direction do sound waves travel?

Answer 4

Particles vibrate parallel to the direction of wave travel.

Question 5

What has to happen for our brains to interpret sounds?

Answer 5

The vibration reaches our ears

Question 6

What is the energy transfer in a loudspeaker?

Answer 6

Electrical to Kinetic

Question 7

What does an oscilloscope do?

Answer 7

It shows what sounds look like on a screen.

Question 8

What would a wave with high frequency sound like?

Answer 8

Many waves occur in a small amount of time.

Question 9

Name the 3 bones in the ear.

Answer 9

Hammer, Anvil and Stirrup (Ossicles)

Question 10

What is the function of the outer ear?

Answer 10

To funnel the sound towards the ear canal

Question 11

What shape is the cochlea?

Answer 11

Spiral shaped.

Question 12

How to the signals reach the brain?

Answer 12

Signals are passed from the cochlea to the brain through the auditory nerve.

Question 13

What are the units for volume of sound?

Answer 13

Decibels (dB)

Question 14

What is the loudness of a jet plane?

Answer 14

110 decibels

Question 15

Give 3 reasons for hearing loss.

Answer 15

Being exposed to loud noises, head injuries, was, perforating an ear drum.

Question 16

What is the hearing range of humans?

Answer 16

20 to 20,000 Hz

Question 17

What minimum distance should you use to measure sound over?

Answer 17

50 meters

Question 18

What can we use to reduce human timing errors?

Answer 18

Use an electronic timer or data logger and use a large distance.

Question 19

Why should we repeat an experiment 3 times?

Answer 19

To calculate a mean.

Question 20

Which substance does sound travel quickest through?

Answer 20

Solids

Question 21

Describe the arrangement of particles in a gas.

Answer 21

They are spread far apart

Question 22

Which substance does sound travel slowest through?

Answer 22

Gases

Question 23

What is a vacuum?

Answer 23

A space with no particles

Question 24

What is used to remove the air from the bell jar above?

Answer 24

A vacuum pump

Question 25

How long does it take light to reach the Earth from the Sun?

Answer 25

8 minutes and 20 seconds

Question 26

What is the incident ray?

Answer 26

The light going towards something (e.g. a mirror)

Question 27

What travels faster – light or sound?

Answer 27

Light

Question 28

Suggest how you should draw ray diagrams.

Answer 28

With a ruler and a sharp pencil

Question 29

What does the hatch line represent in the diagram above?

Answer 29

The mirror

Question 30

What angle do you draw the normal at?

Answer 30

90 degrees to the surface of the mirror

Question 31

What is the law of reflection?

Answer 31

The angle of incidence is equal to the angle of reflection

Question 32

What is specular reflection?

Answer 32

Reflection of light from a flat smooth surface

Question 33

What is refraction?

Answer 33

Light bending at the surface of a transparent surface.

Question 34

What happens to the speed of light as it passes into a denser medium?

Answer 34

Decreases

Question 35

What happens to the speed of light as it passes into a less dense medium?

Answer 35

Increases

Question 36

True or false: refraction makes swimming pools look deeper than they are.

Answer 36

False- It makes swimming pools look shallower

Question 37

What is the normal?

Answer 37

A line at right angles to a surface

Question 38

Why is it harder to pick up an object from the bottom of the pool than you expect?

Answer 38

Refraction makes objects look closer than they are.

Question 39

How do archer fish catch their prey?

Answer 39

Firing a jet of water at their prey

Question 40

What feature do archer fish have to help them catch their prey?

Answer 40

It has 2 hard parts to its eye, one for seeing in water and one for seeing in air.

Question 41

Why is focusing important?

Answer 41

To get a clear image in our eyes or a camera

Question 42

Give 2 differences between a real image and the object using a pinhole camera.

Answer 42

The image is upside down and smaller than the object.

Question 43

What is the name of the nerve that transfers information from the retina to the brain?

Answer 43

Optic nerve

Question 44

What is the coloured part of the eye called?

Answer 44

Iris

Question 45

What is the function of a lens?

Answer 45

To refract and focus light

Question 46

What does photosensitive mean?

Answer 46

Sensitive to light

Question 47

Name 3 places we would find lenses.

Answer 47

Cameras, telescopes, binoculars, microscopes and corrective glasses

Question 48

What are the 2 types of lenses?

Answer 48

Convex and concave

Question 49

What does a prism do?

Answer 49

It splits white light into different colours, called dispersion

Question 50

What are the 7 colours of the spectrum?

Answer 50

Red Orange Yellow Green Blue Indigo Violet

Question 51

What are the primary colours of light?

Answer 51

Red, green and blue

Question 52

What are the secondary colours of light?

Answer 52

Cyan, Yellow and Magenta

Question 53

How do we make white light?

Answer 53

Mix the 3 primary colours of light together

Question 54

What colour does a red apple reflect?

Answer 54

Red light

Question 55

What colour will white paper appear in green light?

Answer 55

Green

Question 56

Why do objects appear black?

Answer 56

If they absorb all colours and reflect none.