M4- C11

Question 1

progressive wave

Answer 1

a wave in which the peaks and troughs, or compressions and rarefactions, move through the medium as energy is transferred

Question 2

longitudinal wave

Answer 2

a wave in which the medium is displaced in the same line as the direction of energy transfer- oscillations of the same medium particles are parallel to the direction of the wave travel
compression and rarefraction
sound waves

Question 3

transverse wave

Answer 3

a wave in which the medium is displaced perpendicular to the direction of energy transfer- oscillations are normal to the direction of travel of the wave
peaks and troughs
eg. water, EM

Question 4

displacement

Answer 4

distance from the equilibrium position in a particular direction; a vector, so has either +/- value

Question 5

amplitude

Answer 5

maximum displacement from the equilibrium position (can be +/-)

Question 6

wavelength

Answer 6

minimum distance between 2 points in phase on adjacent waves

e.g.one peak to another

Question 7

period

Answer 7

the time taken for 1 oscillation

or time taken for wave to move one whole wavelength past a given point

Question 8

frequency

Answer 8

the number of wavelengths passing a given point per unit time

Question 9

wave speed

Answer 9

the distance travelled by he wave per unit time

Question 10

phase difference

Answer 10

the difference between the displacements of particles along a wave
or the difference between the displacements of particles on different waves, measured i degrees or radians, with each complete cycle or a difference of one wavelength representing 360 or 2Pi radians

Question 11

antiphase

Answer 11

if particles are oscillating completely out of step with each other (one reaches its maximum positive displacement at the same time as the other reaches its maximum negative displacement)

Question 12

reflection

Answer 12

occurs when a wave changes direction at a boundary between 2 different media, remaining in the original medium

Question 13

law of reflection

Answer 13

i=r

angle of incidence = angle of reflection

Question 14

refraction

Answer 14

occurs when a wave changes direction as it changes speed when it passes from one medium to another

Question 15

diffraction

Answer 15

when waves pass through a gap or travel around an obstacle, they spread out

Question 16

polarisation

Answer 16

the phenomenon in which oscillations of a transverse wave are limited to only one plane

Question 17

plane polarised

Answer 17

description of a transverse wave in which the oscillations are limited to only one plane

Question 18

partially polarised

Answer 18

description of a transverse wave in which there are more oscillations in one particular plane, but the wave is not completely plane polarised- occurs when transverse waves reflect off a surface

Question 19

intensity

Answer 19

radiant power passing through a surface per unit area

Question 20

intensity and amplitude

Answer 20

intensity is directly proportional to amplitude^2

Question 21

EM waves

Answer 21

transverse waves and can be plane polarised

Question 22

radio waves

Answer 22

< x10^6

Question 23

microwaves

Answer 23

x10^-1 to x10^-3

Question 24

infrared

Answer 24

x10^-3 to 7x10^-7

Question 25

visible light

Answer 25

7x10^-7 to 4x10^-7

Question 26

ultra violet

Answer 26

4x10^-7 to x10^-8

Question 27

xrays

Answer 27

x10^-8 to x10^-10

Question 28

x ray and gamma ray

Answer 28

x10^-10 to x10^-13

Question 29

gamma ray

Answer 29

x10^-13 to < x10^-16

Question 30

total internal reflection

TIR

Answer 30

occurs at the boundary between 2 different media