Chapter 4&5 mock

Question 1

Formula triangle for wave length

Answer 1

V
F Y

(Upside down y = wave length)

Question 2

Formula triangle for speed

Answer 2

D

S T

Question 3

What do waves transfer

Answer 3

Energy and information

Question 4

What is ultra sound

Give example

Answer 4

Greater than 20,000 hertz, used for scanning birth defects and manufacturing equipment

Question 5

What is infrasound

Give example

Answer 5

Less than 20 hertz and is used to track animals or monitor seismic activity

Question 6

What happens to waves in denser materials

Answer 6

They speed up and bend away from normal

Question 7

What happens to waves in less dense materials

Answer 7

Slows down and bends towards normal

Question 8

Name 3 characteristics of a primary wave

Answer 8

Fast
Compressional
Longitudinal

Question 9

Name 2 characteristics of a secondary wave

Answer 9

Transverse

Slower

Question 10

What can p waves travel through

Answer 10

Solids
Liquids
Gasses

Question 11

What can S waves travel through

Answer 11

Solids only

Question 12

What are sonar waves

Answer 12

Sonar waves are sound waves used for us to be able to “see” In water. They are waves making use of echos, the sound waves are sent off to the environment around it where the waves bounce off objects, when this happens they reflect it back.

Question 13

What can the human ear hear

Answer 13

20-20K hertz

Question 14

Why do they put a gel on the mums tummy before ultra sound scans

Answer 14

Allows scanner to move around and it acts as a medium for the waves to reflect into, more sound will be transmitted.

Question 15

What waves are released after an earth quake

Answer 15

Seismic waves, p then s

Question 16

What do waves transfer

Answer 16

Energy and information

Not matter

Question 17

What is the wavelength of a wave

Answer 17

The distance between a point on one wage and the same point on the next wave- often easiest to measure from Crest to crest

Question 18

What is the amplitude of a wave

Answer 18

It’s maximum disturbance from its undisturbed position

Question 19

What is the frequency of a wave

Answer 19

The number of waves produced by a source each second or the number of waves that pass a certain point each second
Measured In hertz

Question 20

What is the period of a wave

Answer 20

The time it takes to for one complete cycle of vibration to pass a given point

Question 21

Difference between a longitudinal wave and a transverse wave

Answer 21

In longitudinal waves the oscillations are along the same direction as the direction of travel and energy transfer

Whereas in transverse waves the oscillations (vibrations) are at right angles to the direction of travel and energy transfer

Question 22

Example of longitudinal waves

Answer 22

Sound waves

P waves

Question 23

Examples of transverse waves

Answer 23

S waves
Water
Light and all other type of electromagnetic radiation

Question 24

Formula for wave speed

Answer 24

Frequency x wavelength

Question 25

What is refraction

Answer 25

When a wave change speed as it passes through a boundary between two substances with different densities such as air and glass. This causes them to change direction- this is called refraction.

Question 26

What would cause refraction not to happen

Answer 26

If it crossed the boundary at an angle of 90* this is called the normal- in this case, they carry straight on.

Question 27

What are som is of the effects that are a result from refraction

Answer 27

A swimming pool looking shallower than it actually is, bc the light coming from the bottom of the pool bends when it comes out of the surface due to refraction of light.
Twinkling stars due to refraction of light
A pencil partly in water appears bent at the surface of water, because the light coming from the stick bends when it comes out of the surface due to refraction of light.

Question 28

What is the law of reflection

Answer 28

The angle of incidence equals the angle of reflection

E.g.- a wave hits a mirror at an angle of 36, it will be reflected at the same angle 36

Question 29

Examples of reflection

Answer 29

Light reflecting off a mirror
Scenery being reflected off a smooth water surface
Seeing yourself in the mirror

Question 30

Examples of waves being transmitted

Answer 30

Infrared light - tv remotes and can get converted into optical fibres-
Which are used to carry signals, computer data and telephone calls
Microwaves - transmit signals for mobile phone calls
Radiowaves- transmit television and radio programs as they reflect off a charged layer in the atmosphere

Question 31

Examples of waves being absorbed

Answer 31

Light being absorbed in the colour spectrum eg- A blue object absorbs all the colours of the spectrum except blue- it reflects blue

A magenta object object absorbs all the other colours and reflects red and blue

Question 32

Normal hearing range for humans

Answer 32

20hz to 20,000z

Question 33

What are frequencies greater than 20hz called

Answer 33

Ultrasound

Question 34

How is ultrasound used in sonar

Answer 34

A pulse of ultrasound is send out from ship and it bounces off the sea bed or any other objects and an echo is detected. The time it takes for these waves to travel backup indicates that depth of sea bed or object
.

Question 35

Uses of ultrasound in body scanning

Answer 35

Checking condition of foetus
Investigating liver or heart problems
Breaking down kidney stones
Measuring blood flow in body

Question 36

Explain how ultra sound is used in Foetal scanning

Answer 36

Ultrasound energy being reflected onto a screen to create a picture each time it passes from one material to another

Question 37

What are sound with frequencies less that 20hz known as

Answer 37

Infrasound

Question 38

Uses of infra sound

Answer 38

Elephants and giraffes communicate between herds over long distances, scientists use Microphones to track the herds even if hidden in dense forests
Used to detect volcanic eruption
Track meteors through atmosphere

Question 39

What are some seismic waves

Answer 39

Infrasound waves