Post on 29-Jan-2016
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Waves and Radiation Revision
Wave Parameters and Behaviours
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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?