Waves

Question 1

What is a wave?

Answer 1

A wave transfers energy (and information) from one point to another without transferring matter

Question 2

Amplitude

Answer 2

-is half the crest to trough distance. Waves with larger amplitudes carry more energy.
-how far from the equilibrium point the wave has oscillated(vibrated)

Question 3

Wavelength

Answer 3

Distance of one entire oscillation:
-from one crest to the next crest
-distance between any part of a wave and the next part where the wave starts to repeat itself.

Question 4

Crest

Answer 4

the highes part of the wave

Question 5

Throught

Answer 5

lowest point on the wave

Question 6

Frequency

Answer 6

The number of waves produced in 1 second

Question 7

Period

Answer 7

Time to make 1 wave

Question 8

Amplitude symbol and unit?

Answer 8

A
m

Question 9

Wavelength symbol and unit?

Answer 9

λ
m

Question 10

Frequency symbol and unit?

Answer 10

f
Hz

Question 11

Period symbol and unit?

Answer 11

T
s

Question 12

Transverse waves

Answer 12

Oscillations at right angles, perpendicular to direction of wave motion (energy transfer)
Examples: all electromagnetic waves, water waves, waves of string(guitar)

Question 13

Longitude waves

Answer 13

Oscillations occur parallel to direction of energy transfer
Example: sound waves

Question 14

Doppler effect

Answer 14

If a wave source is moving the detected waves will have a different wavelength than if the object was stationary.
-If the wavelength is greater, source moving away
-if wavelength is less, source is moving towards us
-The greater the shift in wavelength the greater the speed of the object.

Question 15

electromagnetic spectrum

Answer 15

Radio waves
microwaves
Inferred
radiation
Visible light
Ultra violet
x-ray
Gamma rays

Question 16

electromagnetic spectrum goes from …. wavelength to …… wavelength
and from ….. frequency to …. frequency

Answer 16

1) long
2) short
3) low
4) high

Question 17

visible spectrum goes from …. wavelength to …… wavelength
and from ….. frequency to …. frequency

Answer 17

1) long
2) short
3) low
4) high

Question 18

visible spectrum

Answer 18

red
orange
yellow
green
blue
indigo
violet

Question 19

Similarities of electromagnetic spectrum

Answer 19

• all Transverse waves
• travel at same speed in a vacuum

Question 20

Law of Reflection:

Answer 20

The angle of incidence = The angle of reflection

Question 21

ray diagram reflection

Answer 21

-First draw the boundary (like a mirror)
-Then the ray of incidence hitting in to the boundary (mirror) at a certain angle
-Then draw the normal and measure the angle of incidence
-The angle of incidence is the same as the angle of reflection so draw the ngle of reflection on the other side and add the reflected ray

Question 22

What happens to wave speed during refraction?

Answer 22

-wave speed slows down when it enters a glass block
-waves will have different speeds for different materials

Question 23

Ray diagram refraction

Answer 23

-First draw the ray of incidence hitting into the glass
-Draw the normal and know that the angle of incidence going from air to glass bends towards the normal
-This new line that was bent towards the normal is called Refracted ray, forming the angle of refraction (from normal to refracted ray)
-Then at the point of refraction on the other side of the glass box draw another normal and bend the ray of refraction away from the normal

Question 24

Can all waves be reflected and refracted?

Answer 24

yes, transverse and longitude

Question 25

Total internal reflection

Answer 25

-The critical angle is when the ray of refraction disapears and is 90oC to the normal
-Then the angle of incident becomes the critical angle
if the angle of incidence is bigger then the critical angle then we get total internal reflection

Question 26

Total internal reflection can only occur when:

Answer 26

• a ray of light travels from a dense material into a less dense material
• the angle of incidence is greater than the critical angle

Question 27

Sound is an example of a Longitudinal or transverse wave.

Answer 27

longitudinal wave

Question 28

Range of human hearing

Answer 28

Frequency 20 – 20,000 Hz
decreases with age

Question 29

Does sound travel faster in liquid solid or gas? why?

Answer 29

In solids because the particles are more densely packed the particles vibrate and collide with each other and the sound waves can get transmitted through material

Question 30

Can sound travel through vacuum? Why?

Answer 30

No because there are no particles to vibrate and collide the waves can’t get transmitted

Question 31

as sound speed up wavelength …. and frequency ….

Answer 31

1) increases
2) doesn’t change

Question 32

wavelength gets ….. as waves speed up (through different densities)

Answer 32

longer

Question 33

wavelength gets …. as waves slow down (through different densities)

Answer 33

shorter

Question 34

higher frequency … pitch

Answer 34

higher

Question 35

amplitude increases volume ……

Answer 35

increases

Question 36

Displaying sound waves

Answer 36

• We can display sound waves by using a combination of a microphone and oscilloscope.
• The Microphone converts sound energy into electrical energy.
• These electrical signals are then displayed on the oscilloscope screen.

Question 37

Measuring the Speed of Sound

Answer 37

• We measure the time it takes for us to hear the clapper which is 100 meter away
• We used a clapper, a stopwatch and a trundle wheel
• We measure the quantities by starting the stopwatch when the clapper made contact and stopped the stopwatch when you hear the sound
• We took 8 repeats
• Speed = distant/time
• Use ear protector on the person using the clapper to block the loud sound so it does not damage your ears