P5.1 Wave behaviour

Question 1

describe amplitude

Answer 1

distance from normal line to maximum displacement

Question 2

describe wavelength

Answer 2

distance from one point on a wave to the same point on the next wave

Question 3

describe frequency

Answer 3

the number of waves that pass a point in one second

Question 4

describe the time period

Answer 4

the amount of time taken for one wave to pass

Question 5

describe the realtionship between wavelength, frequency and wave velocity

Answer 5

(m/s)

Question 6

describe the realtionship between time period and frequency

Question 7

what are the differences between longitudinal and transverse waves?

Answer 7

• longitudunial: direction of energy transfer is parallel to direction of vibration
• transverse: the direction of energy transfer is perpendicular to direcrion of vibration

Question 8

what happens to sound waves when they cross a boundary?

in terms of velocity, frequency and wavelength

Answer 8

when traveling from medium to another velocity and direction can change (refraction)

when travelling into a more dense region: (waves speed up)
* wavelength : moves away from normal, so wavelength increases
* velocity: increases due to chnage in medium (density)
* frequency: always stays the same

Question 9

what three things can happen when a wave hits the boundary between 2 media?

Answer 9

• absorption
• transmitted (refracted)
• reflected

Question 10

what is ultrasound and why is it useful?

Answer 10

• ultrasound operates above 20,00Hz,
• useful because it has a very small wavelngth and so can focus it into a beam

Question 11

Describe the process of ultrasound

image of a foetus

Answer 11

1. transmitter beams ultrasounds into the mother
2. the waves reflect from the different boundaries
3. the machine calculates the distances by using time and velocity to produce an image

Question 12

what happens when a sound wave hits a solid?

Answer 12

• sound is absorbed making particles vibrate
• solid gets a bit hotter

Question 13

describe how the ear detect sound?

Answer 13

1. pinna and ear anal dircet the sound wave to the ear drum
2. ear drum vibrates, making the ossicles vibrate
3. the ossicles amplify the vibration and passes it on to the inner ear through oval window
4. the cochlea contains afluid which transmits the vibration and makes amll hairs inside the cochlea vibrate
5. the hairs are attached to sound detecting cells that release chemical substances
6. makes nerves send a signal down auditory nerve to the brain

Question 14

why does hearing change due to ageing?

Answer 14

you lose the shorter hairs and so it is more difficult to hear higher frequencies

human hearing= 20 - 20,000 Hz

Question 15

how are ripples on water surfaces used to model transverse waves?

Answer 15

• the surface of the wave moves up and down
• the wave travels but the water does not

Question 16

how do you calculate the speed of transverse waves?

Answer 16

wavespeed= frequnecy * wavelength
* wavelength: using a flashlight /ruler
* frequency: number of roatations of motor per second

Question 17

how do you measure the speed of sound

Answer 17

speed= distance/ time
distance: ruler/ trundel wheel from wall to person
time: stopwatch from clap to when echo is heard

Question 18

describe how oscilliscope practical works?