Topic 4 - Waves

Question 1

Waves

Answer 1

Transfer energy and information in the direction they travel without transferring matter

Question 2

Frequency

Answer 2

Number of complete cycles of the wave passing a certain point per second

Question 3

Wavelength

Answer 3

The lenth of a full cycle of the wave(crest to crest or trough to trough)

Question 4

Amplitude

Answer 4

The displacement from the rest position to a crest a trough

Question 5

Period

Answer 5

The number of seconds it takes for one full cycle.

Question 6

Period=

Answer 6

1/Frequency

Question 7

Wavespeed

Answer 7

The speed at which the wave travels

Question 8

Wave speed(m/s) =

Answer 8

Distance/Time

Question 9

What is the wave equation

Answer 9

Wave speed(m/s) = Frequency(hz) x Wavelength(m)

Question 10

Longitudinal waves

Answer 10

Where the vibrations are parallel to the direction of the wave. Have compressions and rarefactions.

Question 11

Transverse waves

Answer 11

The vibrations are perpendicular to the direction of the wave

Question 12

Sound waves are

Answer 12

Longitudinal

Question 13

P-waves are

Answer 13

Longitudinal

Question 14

EM waves are

Answer 14

Transverse

Question 15

Seismic waves are

Answer 15

Transverse

Question 16

Water waves are

Answer 16

Transverse

Question 17

Speed of sound waves practical

Answer 17

Use a signal generator to produce sounds with a specific frequency. Attach two microphones to an oscilloscope to find the wavelength of the sound waves. Then use v = fλ.

Question 18

Speed of water ripples practical.

Answer 18

Use a signal generator attached to the dipper of a ripple tank to create certain frequency waves. Turn on the strobe light and alter its frequency until the wave pattern on the screen stops moving. Measure the distance between lines that are 10 wavelengths apart and find the average wavelength. Then use v = fλ

Question 19

Wave absorbtion effect

Answer 19

The wave transfers energy to the materials energy stores. Often it is transferred to the thermal energy store which leads to heating.

Question 20

Wave transmission effect

Answer 20

The wave carries on travelling through the new material. Often leads to refraction.

Question 21

Wave reflection effect

Answer 21

The wave is sent back away from the material. How echoes are created.

Question 22

Wave refraction effect

Answer 22

When a wave is transmitted through a boundary and changes direction.

Question 23

How does refraction occur

Answer 23

When a wave crosses a boundary into a different density material, it changes speed. This leads to change in direction.

Question 24

Which way does a wave refract

Answer 24

If a wave is travelling along the normal it will change speed but not change direction. If it slows down it bends towards the normal, and if it speeds up it travels away from the normal

Question 25

What determines if a wave get reflected, absorbed etc...

Answer 25

Depends on the wavelength of the wave and the properties of the material

Question 26

How are sound waves produced

Answer 26

Vibrating objects are passed through the surrounding medium as a series of compressions and rarefactions.

Question 27

Eardrum

Answer 27

Sound waves cause it to vibrate

Question 28

Ossicles

Answer 28

Tiny bones in the ear that recieve the vibrations from the ear drum

Question 29

Semicircular canals

Answer 29

From the ossicles to the cochlea

Question 30

Cochlea

Answer 30

Turns vibrations into electrical signals

Question 31

Auditory nerve

Answer 31

Carries elctrical signals to the brain

Question 32

Ultrasound

Answer 32

Sound waves with frequency of more than 20,000Hz

Question 33

Infrasound

Answer 33

Sound waves with frequency of less than 20,000Hz

Question 34

Sonar

Answer 34

Used by boats and submarines to send ultrasound to the surface and measure distance of objects underwater.

Question 35

Foetal scanning

Answer 35

Ultrasound is sent int othe womb to produce a video image of the foetus.

Question 36

Explorations of the earths core

Answer 36

Seismic waves(P and S-waves) act differently so are used to explore the size and properties of the earths inside.

Question 37

How do velocity, frequency and wavelength change and link in sound waves travelling between mediums

Answer 37

When a sound waves is transmitted througha boundary from one medium to another, velocity changes. Frequency doesnt change meaning that wavelength must change. When velocity increases, so does wavelength and vice versa.