YR 9@E SCIENCE REVISION BOOKLET Term 2
Name:
LEARNING INTENTIONS
1. To understand the major points of the topic Light covered in term 2.
2. To revise the content of the Light unit.
3. To be prepared for the mid-year exam.
SUCCESS CRITERIA
1. Successful completion of the booklet.
2. Great Score on the Exam.
YR 9@E SCIENCE REVISION BOOKLET Term 2
1. You are playing pool and you have to pocket the yellow ball by hitting it
with the white ball.
a. How does an understanding of reflection help you to pocket the yellow
ball? Write your response
Angle of I = angle of r. Aiming the ball at the ‘cushion’ to create these angles allows you to
line up the ball to go in the hole
b. On the diagram above, draw an image of your understanding showing
which pocket you will aim for (you can use arrows or lines).
See Diagram
2. Light is a form of energy. All forms of energy have a starting point or source. Name 2
sources of light. State whether your examples are of a luminous or non-luminous
nature.
The Sun
A flame
Both these examples create their own light by the process of heating atoms to cause
photons to be created. Both examples are therefore LUMINOUS
YR 9@E SCIENCE REVISION BOOKLET Term 2
3. The diagram shows four light rays reflecting from a
plane mirror. Each light ray has been given a letter.
Which of the rays is the correct “reflected ray”?
The correct Reflected Ray is line C.
4. If you imagine an atom as a tiny solar system, what part is the “sun”?
The nucleus is like the Sun. It contains the positive protons and neutral neutrons.
5. What parts are the “planets”?
The planets are the negative electrons that revolve around the nucleus.
6. What is the smallest known unit of light?
The smallest known unit of light is the photon. It is formed when an electron falls back from
an outer orbit around the nucleus to a closer one.
7. Complete the reflected rays at the correct angle of reflection. Complete each ray
diagram.
Reflected ray should be heading off this side
of the diagram at the same angle (i) as the
incident ray to the normal.
Do not forget the directional arrows.
i
Mirror
YR 9@E SCIENCE REVISION BOOKLET Term 2
8.
Draw a diagram that shows a mirror with a normal line and a ray of light hitting
the mirror at an angle of incidence of 60 degrees.
i = 60degrees
9.
What is the speed of light in a Vacuum?
300,000 km per second
10. State the law of reflection:
The angle of incidence and the angle of reflection are equal when light reflects off of a
plane mirror
11. Light strikes a mirror’s surface at 20 degrees to the normal. What will the angle of
reflection be? Draw a ray diagram to show your understanding.
Include a Key
N
I
i = 70degrees
r= 70degrees
20 degrees
Angle of reflection equals 70 degrees (90 – 20 = 70)
R
YR 9@E SCIENCE REVISION BOOKLET Term 2
Draw a ray diagram in the following diagrams.
N
I
i
glass
air
r
R
air
vacuum
diamond
water
12. Draw a ray diagram showing light entering from a denser medium to a less dense
medium. Provide suggested measurements for your angles and draw a clear
boundary between the two materials. Your diagram must be fully labelled.
N
I
i
Diamond
glass
air
r
R
YR 9@E SCIENCE REVISION BOOKLET Term 2
13. Complete the diagram.
If you have to add labels
then remember to
number the labels in
order. The Normals are
labelled 1,2,3,4.
N1
Water
Glass
Air
N2
This should also be
applied to all other
labels as well.
N3
Diamond
N4
Vacuum
14. Define the following terms.
(a)
Photon: The basic particle of light and other electromagnetic radiation.
(b)
Angle of Incidence: The angle formed between the Incident Ray and the Normal
(c)
Transparent: Light can pass through the object and you can see through it.
(d)
Opaque: Light cannot pass through the object and you cannot see through it.
(e)
Translucent: Light can pass through the object but you cannot see through it.
(f)
Refraction: The bending of light as it passes from one material (or medium M1)
into another material (medium M2)
(g)
Reflection: Light bouncing off of a mirror and therefore staying in the same
material (or medium)
YR 9@E SCIENCE REVISION BOOKLET Term 2
Calculate Refractive index: using Sin I = Refractive Index
Sin r1
Angle of
Sin i
Incidence (i)
Angle of
Refraction (r)
Sin r
Refractive
Index
degrees
degrees
1
30
0.50
25
0.42
1.19
2
35
0.57
17
0.29
1.97
3
48
0.74
38
0.62
1.19
4
15
0.26
9
0.16
1.63
5
72
0.95
21
0.36
2.64
Can you calculate the missing value
6
20
16. State 1, 2, 3, 4, 5 or 6 as the answer to the following questions.
a. Which material is the most dense? No. 5
b. Which material is the least dense? No. 1 and No. 3
NOTES
1.3