Waves

Question 1

What are transverse waves?

Answer 1

Oscillations are perpendicular to the direction of energy transfer.

Question 2

Examples of transverse waves?

Answer 2

All EM waves

Ripples and waves in water

Question 3

What are longitudinal waves?

Answer 3

Oscillations are parallel to the direction of energy transfer.

Question 4

Examples of longitudinal waves?

Answer 4

Sound waves

Shockwaves

Question 5

What is the frequency?

Answer 5

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

Question 6

What is the equation linking freq and time period?

Answer 6

T = 1/f

Question 7

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

Answer 7

wave speed = frequency x wavelength

Question 8

What is refraction?

Answer 8

Waves chaning direction at a boundary

Question 9

Ripple tank practical?

Answer 9

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

Question 10

Air and glass?

Answer 10

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

Question 11

Air TO glass?

Answer 11

-ray slows down so bends towards the normal

Question 12

glass to air?

Answer 12

-ray speeds up so bends away from normal

Question 13

Side entering the glass first?

Answer 13

-slows while the opposite side continues at faster speef

Question 14

Upon entering the glass?

Answer 14

• speed and wavelength decrease

- frequency stays the same

Question 15

What do white objects do?

Answer 15

reflect all wavelenghts

Question 16

What do black objects do?

Answer 16

Absorb all wavelengths

Question 17

What do transparent objects do?

Answer 17

Transmit light

Question 18

What are colours?

Answer 18

specific wavelengths of light

Question 19

What is a real image?

Answer 19

When the light rays meet at focal point

Question 20

What is a virtual image?

Answer 20

When the light rays not actually at focal point

Question 21

What is a black surface better at?

Answer 21

absorbing and emitting radiation than a white one

Question 22

What is a matt surface better at?

Answer 22

absorbing and emitting radiation than a shiny one

Question 23

What is the perfect black body?

Answer 23

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

Question 24

What do black bodys absorb?

Answer 24

All electromagnetic radiation

Question 25

What are black bodies good for?

Answer 25

emitting radiation

Question 26

The hotter the temperature of bbr?

Answer 26

- The lower the peak - The steeper the initial intensity increase - The higher the intensity of the wavelengths

Question 27

What are sound waves caused by?

Answer 27

vibrating particles | longitudinal wave

Question 28

What does sound travel faster in?

Answer 28

solids

Question 29

Why can't sound travel in space?

Answer 29

- vacuum | - no vibrating particles

Question 30

loudness=

Answer 30

amplitude

Question 31

Freq=

Answer 31

pitch

Question 32

Hearing?

Answer 32

- Sound waves cause ear drum to vibrate - vibrations passed on to cochlea - cochlea turns vibrations into electrical signals which get sent to brain

Question 33

What is the hearing range?

Answer 33

20-20kHz

Question 34

What is human hearing limited by?

Answer 34

- size - shape - material of ear drum

Question 35

What are ultrasounds?

Answer 35

sound waves with frequencies higher than 20,000Hz

Question 36

What are ultrasounds used for?

Answer 36

- prenatal scanning | - depth measurement

Question 37

Depth measurement equation?

Answer 37

depth = speed x time --------------------- 2

Question 38

Why do you divide by 2 for depth measurements?

Answer 38

ultrasounds travels there and back

Question 39

P- waves?

Answer 39

- Longitudinal - Travel through solids and liquids - Faster

Question 40

S- waves?

Answer 40

- Transverse - Travel through solids only - slower

Question 41

The outer core is?

Answer 41

liquid

Question 42

The mantle is?

Answer 42

solid