waves

Question 1

what does light do when it hits a shiny surface

Answer 1

it reflects

Question 2

where are the angles of incidence, reflection and refraction measured

Answer 2

in between the ray and the normal

Question 3

what is the normal

Answer 3

a dashed line drawn at 90° to the surface

Question 4

the law of reflection

Answer 4

angle of incidence = angle of reflection

Question 5

what are the three primary colours

Answer 5

red green and blue

Question 6

what are the secondary colours

Answer 6

magenta yellow and cyan

Question 7

how do you make white light

Answer 7

mix all three primary colours

Question 8

what is refraction

Answer 8

light changing speed and wavelength (and sometimes direction) when it enters a different material

Question 9

what is total internal reflection

Answer 9

when the angle of incidence is above the critical angle, the ray of light will fully reflect back in the material

Question 10

are convex lenses used to correct long or short sight

Answer 10

long

Question 11

are concave lenses used to correct long or short sight

Answer 11

short

Question 12

what way do convex and concave lenses redirect light

Answer 12

convex goes in and concave goes out

Question 13

what do waves transfer

Answer 13

energy

Question 14

what is the highest part of a wave called

Answer 14

crest/peak

Question 15

what is the lowest part of a wave called

Answer 15

trough

Question 16

what is the distance from the crest or trough of a wave to the middle line called

Answer 16

amplitude

Question 17

what way to the vibrations occur in a transverse wave

Answer 17

90° to the direction the wave is travelling

Question 18

what way to the vibrations occur in a longitudinal wave

Answer 18

they occur in the same direction the wave is travelling

Question 19

what is frequency

Answer 19

the number of waves that pass a point per second

Question 20

f=N/t

Answer 20

frequency (Hz) = number of waves / time (s)

Question 21

what is the period of a wave

Answer 21

how long it takes one wave to pass a point

Question 22

f= 1/T

Answer 22

frequency (Hz) = 1 / period (s)

Question 23

v= fλ

Answer 23

speed (ms^1) = frequency (Hz) wavelength (m)

Question 24

what are the 3 things all waves do

Answer 24

reflection, refraction and diffraction

Question 25

when does a wave diffract

Answer 25

when a wave passes through a gap or passes around an object

Question 26

how would you create more diffraction

Answer 26

decease size of the gap the wave passes through or increase wavelength

Question 27

what can sound travel through

Answer 27

solids, liquids, and gases

Question 28

what is the wavelength and frequency like on high and low pitched sound waves

Answer 28

high pitched has high frequency and short wavelengths, low pitched has low frequency and longer wavelengths

Question 29

what is the amplitude like on loud and quiet sound waves

Answer 29

loud sounds have high amplitude, quiet sounds have lower amplitude

Question 30

what is the speed of sound in air

Answer 30

340 ms^1

Question 31

why is the speed of sound in solids and liquids faster than in gases

Answer 31

the particles are closer together

Question 32

what is the range of human hearing

Answer 32

between 20 and 20,000 Hz, but this decreases as we get older

Question 33

what is the sound level (loudness) measured in

Answer 33

decibels dB

Question 34

why do workers in noisy places wear ear defenders

Answer 34

the sound level is often above 85dB which can damage their hearing