waves

Question 1

waves do what

Answer 1

Waves transfer energy from one place to another without transferring matter.

Question 2

amplitude

Answer 2

the maximum displacement from the equilibrium position (the x-axis).

Question 3

wavelength

Answer 3

the distance of one entire oscillation of that wave.

Question 4

time period

Answer 4

the time it takes for one entire oscillation of a wave.

Question 5

frequency

Answer 5

The total number of wave cycles completed in one second

Question 6

The formula for frequency is:

Answer 6

frequency=1/time

(time when one complete oscillation)​


Question 7

The formula for wave speed is:

Answer 7

wave speed (metre/second, m/s) =
frequency (hertz, Hz) × wavelength (metre, m)

Question 8

parallel to the direction of energy transfer is a:

Answer 8

Longitudinal

Question 9

perpendicular to the direction of energy transfer is a

Answer 9

Transverse wave

Question 10

examples of transverse wave

Answer 10

light
radio
ripples
waves on strings for guitar

Question 11

examples of longitudinal waves

Answer 11

sound
seismic p waves

Question 12

Describe one piece of evidence that shows when a sound wave travels through the air it is the wave and not the air itself that travels

Answer 12

A vibrating drum skin does not move the air away to create a vacuum (around the drum).

Question 13

period

Answer 13

length of time it takes one wave to pass a given point

Question 14

velocity

Answer 14

speed of the wave in the direction that its travelling

Question 15

Describe how to measure the velocity of sound in air and
ripples on water surfaces

Answer 15

sound- stand infront of large wall measure the time it takes for an echo of loud sound to reach you

velocity-measure the time it takes for a wave to travel between two fixed points such as buoys

Question 16

Calculate depth or distance from time and wave velocity

Answer 16

distance=speedx time

is there is an echo divide by 2

Question 17

reflection

Answer 17

when a wave bounces off a boundry

Question 18

refraction

Answer 18

when a wave passes into an new material but changes speed and direction when travelling

Question 19

transmission

Answer 19

when a wave passes through a material and is not absorbed or reflected

Question 20

absorbtion

Answer 20

when a wave dissapears as the energy it is carrying is transferred into a new material

Question 21

Explain how waves will be refracted at a boundary in terms of
the change of direction and speed

Answer 21

When wave crosses boundary between materials at angle changes direction which means refracted

2. Waves crosses a high density material a slower wave
   wave crossing low density material will have a higher speed

3 how much wave speeds up or slows down will affect refracted.

wave crosses boundry and slows down bends towards normal
sppeds up bend away from normal

5. The wavelength of wave changes when refracted, but frequency stays the same
6. If the wave is travelling along the normal it will change speed, but it’s not refracted

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Question 22

Recall that different substance may absorb, transmit, refract or reflect EM waves in ways that vary with WL

Answer 22

different WL will A,T,R differently
just like how light waves through glass will be A,TR etc

Question 23

Describe the processes which convert wave disturbances between sound waves and vibrations in solids

Answer 23

Sound example longitudinal wave -
compressions (regions of higher density)
rarefactions (lower density).
These cause changes in pressure,
vary in time with the wave.
waves hit the solid, the variations in pressure cause the surface of the solid to vibrate in sync with the sound wave.

Question 24

Explain why such processes only work over a limited frequency range, and the revelance of this to human hearing

Answer 24

NOT ABOUT THE VOLUME (like tv volume)
as humans range of frequencies that we can hear. animals have different.
Hair cells become damaged which cant receive the vibrations

Question 25

Recall that sound with frequencies greater than 20 000 hertz, Hz, is known as

Answer 25

ultra sound

Question 26

Recall that sound with frequencies less than 20 hertz, Hz, is known as

Answer 26

infrasound

Question 27

explain uses of ulta sound

Answer 27

Sonar uses ultrasound detect objects underwater The sound wave is reflected off the ocean bottom The time sound wave return used to calculate the depth of the water The distance the wave travels is twice the depth of the ocean This is the distance to the ocean floor x2 Foetal Scanning ultrasound used images of a foetus in the wombmade up of a transducer that produces and detects a beam of ultrasound waves into the body waves are reflected back to the transducer by different boundaries between tissues in the path of the beam For example, the boundary between fluid and soft tissue or tissue and bone exploration of earths core p waves - move faster than s waves longitudinal but cant pass gas low frequency sound waves known as infrasound s waves S-waves are slower than P-wave unable to travel through liquid only travel through solids

Question 28

explain uses of ulta sound

Answer 28

Sonar uses ultrasound detect objects underwater The sound wave is reflected off the ocean bottom The time sound wave return used to calculate the depth of the water The distance the wave travels is twice the depth of the ocean This is the distance to the ocean floor x2 Foetal Scanning ultrasound used images of a foetus in the wombmade up of a transducer that produces and detects a beam of ultrasound waves into the body waves are reflected back to the transducer by different boundaries between tissues in the path of the beam For example, the boundary between fluid and soft tissue or tissue and bone exploration of earths core p waves - move faster than s waves longitudinal but cant pass gas low frequency sound waves known as infrasound s waves S-waves are slower than P-wave unable to travel through liquid only travel through solids

Question 29

what does the discovery of p and swaves show

Answer 29

The mantle is solid – this is because both types of wave can pass through it The outer core of the Earth is liquid – hence no S-waves can penetrate it The inner core is solid – this is due to the size and positions of these shadow zones which indicate large refraction taking place

Question 30

Describe how changes, if any, in velocity, frequency and wavelength, in the transmission of sound waves from one medium to another are inter-related

Answer 30

Velocity of sound is directly proportional to the wavelength. Thus, if the velocity of sound doubles when it travels from one medium to another, its wavelength also doubles. The frequency of sound depends upon the source of sound, not the medium of propagation. Hence, it does not change.

Question 31

suitability of equipment to measure the speed, frequency and wavelength of a wave in a solid

Answer 31

suspend metal rod horizontally using clamp stand and rubber band hit one end with hammer get frequency app and note peak frequency measure length of rod wavelength=length x 2 use frequency and wavelength to calculate speed

Question 32

suitability of equipment to measure the speed, frequency and wavelength of a wave in a liquid

Answer 32

set up ripple tank with straight dipper near one side of tank fasten ruler to one of sides so u see markings vary the current until see waves with wavelength half as long as tank count waves form in 10 seconds use the ruler to estimate the wavelength of waves use wavelength and frequncy to work out speed mark 2 points on same edege as ruler use stop watch to mesaure the time for it to go from one mark to the other

Question 33

ear path

Answer 33

sound waves move along ear canal and hit our eardrum causes vibrate which will transmit through osicles through the semi circular canals and into cochlea which converts into signals

Question 34

what happens when ultra sound hits medium

Answer 34

partial reflection

Question 35

Ppl trying to measure spped of sound in air How could they imrpve the method

Answer 35

Make the distance longer Cause 50m too short to produce measureable time Give more accurate result

Question 36

Describe how hitting the rod causes sound wave to travel along the inside of the rod

Answer 36

Particles at end vunrate in fixed positions which cause neighbouring particles to vibrate

Question 37

Describe how dolphin use sound waves to see which object closest

Answer 37

Emit and recieve sound reflected from object Differency in time to recieve echo Sound recieved in shorter time is closest

Question 38

Explain how p and s waves show about density and nature of earths core

Answer 38

Where p and s waves detect P waves arrive before s Solid cause s waves only travel in solid Mantle must be solid Waves refract so mantle gets more dense as u go deeper No waves Must be liquid cause no waves go thru liquid Core must be liquid R refracted at the boundry Only p waves Arrive at different times cause travelled at different speeds Very centre is solid cause travel faster than those that went tru liquid