Medical Physics S2

Question 1

What is sound?

Answer 1

A form of energy transferred as a wave through solids, liquids and gases9

Question 2

How fast does sound travel through air?

Answer 2

Sound travels at 340 metres per second in air

Question 3

What is sound caused by?

Answer 3

Vibrations

Question 4

What is the frequency?

Answer 4

Number of vibrations in one second is called the frequency of the sound, its measured in hertz (Hz)

Question 5

What frequency do high-pitched sounds have?

Answer 5

High frequency

Question 6

What frequency do low-pitched sounds have?

Answer 6

Low frequency

Question 7

What Hz can humans hear between?

Answer 7

20 to 20,000 Hz

Question 8

What are vibrations over 20,000 called?

Answer 8

An ultrasound

Question 9

What is the volume?

Answer 9

The size of waves in Hz

Question 10

What is sound level measured in?

Answer 10

Decibels (dB)

Question 11

What decibels damages your ears?

Answer 11

Anything above 90 dB can damage your ears

Question 12

What is light?

Answer 12

Light is a form of energy transferred as a wave

Question 13

Can light pass through a vaccum?

Answer 13

Yes

Question 14

How fast does light travel?

Answer 14

300 million metres per sec

Question 15

How does light travel?

Answer 15

In straight lines

Question 16

How can you change the direction of light?

Answer 16

If its reflected or refracted

Question 17

Lenses only work because..?

Answer 17

of refraction

Question 18

What do convex lenses do?

Answer 18

Cause light to converge (come together)

Question 19

What do concave lenses do?

Answer 19

Cause light to diverge (move apart)

Question 20

How do your eyes send messages to your brain?

Answer 20

Eyes convert light into electrical signals interpreted by the brain

Question 21

What are the main parts of the eye?

Answer 21

Cornea; pupil; iris; lens; retina; and optic nerve

Question 22

What do long-sighted people see?

Answer 22

They see distant objects clearly but close objects are blurred

Question 23

How do you fix long-sighted?

Answer 23

Convex lenses

Question 24

What do short-sighted people see?

Answer 24

They see close objects clearly but distant objects are blurred

Question 25

How do you fix short-sighted?

Answer 25

Concave lenses

Question 26

What is white light made up of?

Answer 26

Of different colours - ROYGBIV the rainbow spectrum

Question 27

What are laser beams?

Answer 27

LASER beams are very narrow beams of light energy of a single
colour

Question 28

What is the EM spectrum?

Answer 28

Family of waves similar to light but invisible to the human eye

Question 29

Whats on the EM spectrum?

Answer 29

Radio/TV; Microwave; Infrared (IR); Visible light; Ultraviolet (UV); X-rays; Gamma rays;

Question 30

What is Infrared (IR)?

Answer 30

Heat energy

Question 31

What is Ultraviolet (UV)?

Answer 31

From the sun, causes sun burn and skin cancer

Question 32

What are X-rays?

Answer 32

Can penetrate the body, can be dangerous

Question 33

What are Gamma-rays?

Answer 33

Can be dangerous

Question 34

What is medical imaging?

Answer 34

Different waves used to give medical information

Question 35

What is an Ultrasound?

Answer 35

• Sound waves reflect off bony material
• Used to examine babies in the womb
• Can monitor blood flow

Question 36

How is Infrared used in medicine?

Answer 36

• Measure body temperature
• can show tumours and arthritis

Question 37

How is UV used in medicine?

Answer 37

Detecting skin conditions

Question 38

How are X-rays used in medicine?

Answer 38

• Internal images
• energy absorbed by bony material
• used to examine breaks and fractures

Question 39

What is a CAT (Computed Axial Tomography) scanner do in medicine?

Answer 39

• 3-dimensional X-ray images of the whole body

Question 40

What does a MRI (Magnetic Resonance Imaging) scanner do in medicine?

Answer 40

• 3-dimensional images of the soft tissue of the whole
• good for brain images

Question 41

What does Ultrasound treat?

Answer 41

They can break up kidney stones

Question 42

What does an IR treat?

Answer 42

Sports injuries

Question 43

What does UV treat?

Answer 43

Skin conditions

Question 44

What does X-ray treat?

Answer 44

It kills cancer cells