Transcript Document

Waves and Radiation Revision
v = fλ
v=d÷t
crest
Wave Parameters and Behaviours
Wavelength
(metres m)
Number of Waves
passing a point per
second is called
the Frequency
Axis
trough
amplitude A
(metres
m)
Waves per Second – Hertz( Hz)
speed v
(metres/second
m/s)
The time for one
wave is called the
period
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.
v = fλ
Increasing wavelength
Increasing frequency and energy
QU 6
Qu 7
Qu 8
Qu 9
Light
Angles always measured from the normal
air
glass
Reflection
Angle of incidence =
angle of reflection
Refraction – change of speed
when going into a different
material
Convex lens
Concave lens
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
refraction
Smaller than
critical angle
Critical angle –
when refracted
angle is 90o
Larger than
critical angle
Optical fibre
Qu 10
Open ended question
Piggy in Lord of the Flies is short-sighted. Piggy's glasses are
used to start bonfires.
Discuss
Qu 11
Qu 12
13.
Nuclear Radiation
Label the atom and give
the charge of each :proton
neutron
electron
What is an ion?
How can ionization happen?
Types of nuclear radiation
• Alpha Particle (α)
-
• Beta Particle (β)
• Gamma Ray (γ)
1. Which causes most ionisation?
2. What is the most that each can penetrate?
Sources of background
radiation
Natural
Artificial
D = E÷ m
Summary
.
.
H = Dwr
.
H=H÷t
Half life – the time for the activity of the source to half.
Y-Values
120
GBq giga
MBq mega
kBq kilo
Activity (MBq)
100
80
60
mSv milli
µSv micro
nSv nano
40
20
0
0
20
40
60
80
Time (hours)
Time from start (hours)
0 add half life
What is the activity after 4
half lives?
50
100
150
200
Activity(MBq)
100
Splitting atom