Waves

Question 1

what are waves

Answer 1

they transfer energy and information without transferring matter

Question 2

what 5 factors are used to describe a wave

Answer 2

frequency
speed
wavelength
amplitude
period

Question 3

what is frequency (and unit)

Answer 3

the number of waves passing a point each second (Hz)

Question 4

what is wavelength

Answer 4

the distance between 2 crests of a wave

Question 5

what is amplitude

Answer 5

the distance from the middle of the wave to the top

Question 6

what is the equation to find the period of a wave

Answer 6

1 / Frequency

Question 7

what are the 2 different types of waves

Answer 7

longitudinal and transverse

Question 7

give 2 examples of a longitudinal wave

Answer 7

sound waves and seismic P waves

Question 8

what is a longitudinal wave

Answer 8

where the particles move in the direction the energy transfers and they move back and forth to transfer energy

Question 9

what are 2 examples of a transverse wave

Answer 9

electromagnetic waves
seismic S waves

Question 10

what is a transverse wave

Answer 10

where the waves move perpendicular to the direction of the energy transfer

Question 11

what are the 2 equations to find the speed of a wave

Answer 11

speed = frequency * wavelength
speed= distance / time

Question 12

what are 2 ways to calculate the speed of sound in

Answer 12

using an echo
using 2 microphones and an oscilloscope

Question 13

how can you calculate the speed of sound using 2 microphones and an oscilloscope, in 5 steps

Answer 13

1. set up the microphones one in front of the other at different distances in a straight line from the loudspeaker
2. set the frequency of the sound from the loudspeaker to a known value
3. display the 2 waveforms on the oscilloscope and measure the distance between the microphones
4. move the microphones part by 1 wavelength
5. use the formula: speed = frequency * wavelength

Question 14

what method can you use to figure out the speed of ripples on a water surface

Answer 14

use a ripple tank and a strobe light

Question 15

what 4 things can happen to a wave when it reaches a boundary

Answer 15

reflected, refracted, transmitted, absorbed

Question 16

give an instance when sound waves are transmitted

Answer 16

when sound travels through materials with similar densities

Question 17

give an instance when sound waves are absorbed

Answer 17

depends on the material and the wavelength of the sound

Question 18

give an instance when sound waves are reflected

Answer 18

where there is a big difference in the densities of the materials

Question 19

why does refraction occur

Answer 19

as sound will travel slower in denser material

Question 20

what is denser warm air or cool air

Answer 20

warm air is denser

Question 21

what is the hearing range of a human

Answer 21

20Hz to 20 000 Hz

Question 22

WATCH COGNITO VIDEO ON EAR

Answer 22

https://cognitoedu.org/coursesubtopic/p2-gcse-edexcel-h-t_4.16

Question 23

what is an ultrasound wave

Answer 23

soundwaves that are higher than 20,000 Hz

Question 24

what is infrasound

Answer 24

lower than 20 Hz

Question 25

what is the use of infrasound

Answer 25

used to find the structure of rocks beneath the earth’s crust

Question 26

what are 2 uses of ultrasound

Answer 26

sonar
pre-natal scans

Question 27

how is ultrasound used for pre-natal scans

Answer 27

they are used to make images inside the body, the waves are sent into the woman’s body and some of the sound is reflected each time it meets a layer of tissue with a different density, which can be used to make a picture

Question 28

how is ultrasound used in sonar

Answer 28

sonar uses ultrasound pulses to find the water’s depth beneath a ship. the sonar equipment measures the time between sending the sound and detecting its echo and uses it to calculate the distance