unit 1: physics

Question 1

what does oscillation mean

Answer 1

repetitive motion

Question 2

what’s a complete oscillation

Answer 2

travelling from one side to the opposite side and back to the original position

Question 3

what is period time

Answer 3

time for one complete cycle
1/F

Question 4

what is amplitude

Answer 4

maximum displacement always measured from the centre

Question 5

what’s wavelength

Answer 5

distance between two consecutive points where oscillations are in phase with one another

Question 6

travelling one wavelength takes how many cycles?

Answer 6

one

Question 7

when energy is being transferred , is matter transferred?

Answer 7

no

Question 8

in a longitudinal wave how do oscillations travel?

Answer 8

back and forth along the direction of propagation

Question 9

in a transverse wave how do oscillations travel

Answer 9

at right angles to the direction of propagation - up and down or side to side

Question 10

in longitudinal waves what do the oscillations cause

Answer 10

compressions and rarefactions

Question 11

what does compression mean?

Answer 11

particles are close together

Question 12

what does rarefactions mean

Answer 12

particles are far apart

Question 13

how does thicker stringers effect the speed and note

Answer 13

slower speed and a lower note

Question 14

how does tighter strings effect the note and speed

Answer 14

faster speed and a higher note

Question 15

what is the speed of light

Answer 15

2.998 x 10^8 ms-1

Question 16

does light travel slower or faster in liquid and gas

Answer 16

slower

Question 17

what does the equation c/v = n give

Answer 17

refractive index of a medium

Question 18

what are wave fronts

Answer 18

• lines drawn to join points in a wave where all of the oscillations are in phase
  -spaced one wavelength apart
  -move forward in a direction that is perpendicular to the wave front

Question 19

what is interference

Answer 19

a detectable pattern of different strengths of wave oscillations

Question 20

what is superposition

Answer 20

waves from two different sources that cross and their amplitudes are added together

Question 21

how is path difference created

Answer 21

dividing a light source so that separate rays of light travel at different paths

Question 22

what does path difference create

Answer 22

phase difference

Question 23

how does the path difference increase

Answer 23

as the angle through which a grattings caters the light is increased

Question 24

what happens when the path difference equals a whole number

Answer 24

the light rays will be in phase and constructive interference ( a bright fringe) will occur

Question 25

what happens when light has a mixture of wavelengths

Answer 25

condition for constructive interference occurs at different angles for each wavelength so a set of coloured lines is produced

Question 26

what are stationary waves

Answer 26

two progressive waves moving in opposite directions and superimposed one on the other.

Question 27

what is the result of two stationary waves

Answer 27

fixed pattern of antinodes and nodes

Question 28

what is a resonator

Answer 28

store wave energy by reflecting the wave back on itself to form a stationary wave pattern

Question 29

when are resonators efficient

Answer 29

only receive energy from a source that has a frequency close to one of their own natural frequencies which is called resonance.

Question 30

what waves do string instruments use in stretched strings

Answer 30

stationary waves to make a resonator

Question 31

the fixed ends of strings are?

Answer 31

nodes

Question 32

what instruments use longitudinal waves

Answer 32

pipe organs , woodwind , brass

Question 33

open ends of pipes are?

Answer 33

antinodes

Question 34

what are optical fibres?

Answer 34

high density glass that can carry light signals long distances without loosing any light through their sides

Question 35

what is the critical angle

Answer 35

least angle of incidence at which total internal reflection occurs

Question 36

when does the critical angle apply

Answer 36

when light tries to leave an optically dense medium at a boundary into a less dense medium