Waves and Radiation Revision

Wave Parameters and Behaviours

trou

gh

Number of Waves passing a point per second is called theFrequenc

yWaves per Second – Hertz( Hz)

Wavelength

amplitude AAxis

crest

speed v

(metresm)

(metres m)

(metres/secondm/s)

The time for one wave is called the

period

v = fλ v = d ÷ t

Diffraction

Qu 1

Qu 2

Qu 3

steel

Qu 4

Qu 5

Electromagnetic Spectrum

All electromagnetic waves travel at 300 000 000 ms-1 through a vacuum. (3 x 108 ms-1) and can travel through a vacuum.

Increasing wavelength

Increasing frequency and energy

v = fλ

QU 6

Qu 7

Qu 8

Qu 9

Light

ReflectionAngle of incidence = angle of reflection

Refraction – change of speed when going into a different material

air

glass

Angles always measured from the normal

Concave lensConvex lens

refraction

Critical angle – when refracted angle is 90o

Smaller than critical angle

Larger than critical angle

When the angle in the air gets to 90o it can no longer be refracted and is then reflected. This is called total internal reflection.

total internal reflection.

Optical fibre

Open ended questionPiggy in Lord of the Flies is short-sighted. Piggy's glasses are used to start bonfires.

Discuss

Qu 10

Qu 11 Qu 12

13.

Nuclear Radiation

Label the atom and give the charge of each :- proton

neutronelectron

What is an ion?How can ionization happen?

Types of nuclear radiation

• Beta Particle (β)

• Gamma Ray (γ)

-

• Alpha Particle (α)

1. Which causes most ionisation?2. What is the most that each can penetrate?

Sources of background

radiation

Natural Artificial

.

SummaryD = E÷ m H = Dwr

H = H ÷ t.

.

Half life – the time for the activity of the source to half.

0 10 20 30 40 50 60 700

20

40

60

80

100

120Y-Values

Time (hours)

Activ

ity (M

Bq)

GBq gigaMBq megakBq kilo

mSv milliµSv micronSv nano

Time from start (hours) Activity(MBq)

0 add half life 100

50

100

150

200

What is the activity after 4 half lives?

Splitting atom