Chapter 11 Waves 1

Question 1

What is the differerence between P waves and S waves?

Answer 1

P waves are longitudinal
S waves are transverse

Question 2

What is a similarity between P waves and S waves?

Answer 2

they are both progressive waves

Question 3

What is a progressive wave?

Answer 3

An oscillations that travels through matter.
They transfer energy from one place to another?

Question 4

What is a transverse wave?

Answer 4

A wave in which the oscillations or vibrations are perpendicular to the direction of energy transfer

Question 5

What are two properties of a transverse wave?

Answer 5

Peaks and troughs

Question 6

What are two examples of a transverse wave?

Answer 6

Water wave
any electromagnetic wave
microwaves, gamma rays etc

Question 7

What is a longitudinal wave?

Answer 7

A wave in which the vibrations are parallel to the direction of energy transfer

Question 8

What is an examples of longitudinal waves?

Answer 8

Sound waves

Question 9

What is Amplitude?

Answer 9

maximum distance from the equilibrium position

Question 10

What is time period?

Answer 10

The time taken for the wave to move one whole wave length from a given position

Question 11

What is frequency?

Answer 11

the number of wavelengths passing a given point per unit time

Question 12

What is the wave equation?

Answer 12

Wavespeed = Wavelength x frequency

Question 13

What is the frequency equation relating to time period?

Answer 13

frequency = 1 / time period

Question 14

what is the unit of frequency?

Answer 14

Hertz (Hz)

Question 15

What is phase difference?

Answer 15

the difference between displacement of a particle on two different waves

Question 16

What is the equation for phase difference between two points on a wave?

Answer 16

Phase difference = ( distance / wavelength ) x 360degrees

Question 17

When does Reflection occur?

Answer 17

when a wave changes direction at the boundary between two media?

Question 18

What is an example of reflection?

Answer 18

When light reflects through a mirror?`

Question 19

What is the law of reflection?

Answer 19

the angle of incidence = the angle of reflection

Question 20

What is refraction?

Answer 20

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

Question 21

What is an example of refraction?

Answer 21

When a soundwave speeds up when they enter a denser medium

Question 22

How does refraction affect wavelength

Answer 22

as the wave slows down when they refract its wavelength decreases

Question 23

how does refraction work in water?

Answer 23

when a water wave enters shallower water, it slows down and the wavelength gets shorter

Question 24

What is diffraction?

Answer 24

when a wave travels through a gap or travel around an obstacle they diffract and spread out.

Question 25

What is polarisation?

Answer 25

particles vibrate in one direction which confines the wave to a single plane

Question 26

Can longitudinal waves be plane polarised?

Answer 26

the oscillations are already limited to one plane due to them being parallel in the direction of energy transfered

Question 27

What is partial polarisation?

Answer 27

When a transverse wave is oscillating in one plane but it is not plane polarised

Question 28

What is intensity?

Answer 28

the radiant power passing through a surface per unit area

Question 29

What is the unit of intensity?

Answer 29

Watt per square meter squared

Question 30

what is the equation for intensity?

Answer 30

Intensity = Power / Area

Question 31

How are intensity and amplitude related?

Answer 31

Intensity is proportional to amplitude^2

Question 32

Describe how a ripple tank might be used to investigate diffraction

Answer 32

● Create water waves in the tank. ● Vary the size of a gap for them to pass through. ● Note how the direction of the waves passing through changes.

Question 33

What is an EM wave?

Answer 33

electric and magnetic fields oscilating at right angles

Question 34

How are the electromagnetic waves ordered

Answer 34

from longest wavelength to shortest

Question 35

which EM wave has the largest wavelength?

Answer 35

Radiowaves

Question 36

which EM waves has the shortest wavelength?

Answer 36

gamma rays

Question 37

What is meant by the refractive index of a material?

Answer 37

The refractive index is a measure of how fast light travels in a material compared to its speed in a vacuum.

Question 38

What equation can be used to find refractive index of a material?

Answer 38

n = c/v Where n = refractive index, c = speed of light, v = velocity in the material

Question 39

What is the name given to the angle of incidence at which the light will reflect off a boundary rather than refracting in the medium?

Answer 39

The critical angle. sinC = 1/n Where C = critical angle, n = refractive index of the material being passed into

Question 40

What is the name given to what happens to light at angles greater than the critical angle?

Answer 40

Total internal reflection.

Question 41

Waves can ‘superpose’ - what does this mean?

Answer 41

Two waves in the same place (ie. one on top of the other) will combine.