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Flashcards in Waves Deck (42)
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1
Q

What are transverse waves?

A

Oscillations are perpendicular to the direction of energy transfer.

2
Q

Examples of transverse waves?

A

All EM waves

Ripples and waves in water

3
Q

What are longitudinal waves?

A

Oscillations are parallel to the direction of energy transfer.

4
Q

Examples of longitudinal waves?

A

Sound waves

Shockwaves

5
Q

What is the frequency?

A

The number of complete waves passing a certain point per second.

6
Q

What is the equation linking freq and time period?

A

T = 1/f

7
Q

What is the equation linking wave speed, freq and wavelength?

A

wave speed = frequency x wavelength

8
Q

What is refraction?

A

Waves chaning direction at a boundary

9
Q

Ripple tank practical?

A
FREQUENCY
-Take slow motion video of waves
-count waves passing point in 10 seconds
-freq=no of waves/ 10
WAVELENGTH
-Take camera image
-count number of waves over 50 cm
-wavelength= 30/no of waves
WAVESPEED
-speed=freq x wavelength
10
Q

Air and glass?

A

-Air is less dense than glass so can pass more easily through it

11
Q

Air TO glass?

A

-ray slows down so bends towards the normal

12
Q

glass to air?

A

-ray speeds up so bends away from normal

13
Q

Side entering the glass first?

A

-slows while the opposite side continues at faster speef

14
Q

Upon entering the glass?

A
  • speed and wavelength decrease

- frequency stays the same

15
Q

What do white objects do?

A

reflect all wavelenghts

16
Q

What do black objects do?

A

Absorb all wavelengths

17
Q

What do transparent objects do?

A

Transmit light

18
Q

What are colours?

A

specific wavelengths of light

19
Q

What is a real image?

A

When the light rays meet at focal point

20
Q

What is a virtual image?

A

When the light rays not actually at focal point

21
Q

What is a black surface better at?

A

absorbing and emitting radiation than a white one

22
Q

What is a matt surface better at?

A

absorbing and emitting radiation than a shiny one

23
Q

What is the perfect black body?

A

An object that absorbs all of the radiation that hits it. No radiation is reflected or transmitted

24
Q

What do black bodys absorb?

A

All electromagnetic radiation

25
Q

What are black bodies good for?

A

emitting radiation

26
Q

The hotter the temperature of bbr?

A
  • The lower the peak
  • The steeper the initial intensity increase
  • The higher the intensity of the wavelengths
27
Q

What are sound waves caused by?

A

vibrating particles

longitudinal wave

28
Q

What does sound travel faster in?

A

solids

29
Q

Why can’t sound travel in space?

A
  • vacuum

- no vibrating particles

30
Q

loudness=

A

amplitude

31
Q

Freq=

A

pitch

32
Q

Hearing?

A
  • Sound waves cause ear drum to vibrate
  • vibrations passed on to cochlea
  • cochlea turns vibrations into electrical signals which get sent to brain
33
Q

What is the hearing range?

A

20-20kHz

34
Q

What is human hearing limited by?

A
  • size
  • shape
  • material of ear drum
35
Q

What are ultrasounds?

A

sound waves with frequencies higher than 20,000Hz

36
Q

What are ultrasounds used for?

A
  • prenatal scanning

- depth measurement

37
Q

Depth measurement equation?

A

depth = speed x time
———————
2

38
Q

Why do you divide by 2 for depth measurements?

A

ultrasounds travels there and back

39
Q

P- waves?

A
  • Longitudinal
  • Travel through solids and liquids
  • Faster
40
Q

S- waves?

A
  • Transverse
  • Travel through solids only
  • slower
41
Q

The outer core is?

A

liquid

42
Q

The mantle is?

A

solid