Revision for Forces unit
Light and Sound (summary)
Light carries ______and travels as a ______.
Light waves travel in ______.
We see some objects by ______
Complete the diagram to
show how light reaches the
eye.
We see other objects ______
Complete the diagram to
show how light reaches the
eye.
Complete the diagram to show how light passes through the glass block.
TAGAGA stands for ______
Add arrows to the diagram showing how the fish sees the fly.
Complete the diagram showing how white light is split up as it passes through the prism
The order of the colours
R___, O_____, ______, ______, ______, ______, ______
Explain why a red dress looks red.
______
Complete the following table
Primary colours / Secondary ColourYellow
Cyan
Magenta
The following is a picture of a person looking at a magenta ball. Complete the diagram showing why the ball looks magenta.
Complete the table showing how the objects would look under the filters.
Object colour / Colour filter / AppearanceRed ball / Red
Red ball / Green
Blue ball / Blue
Blue ball / Magenta
Green apple / Cyan
Green apple / Magenta
Red and blue tie / Red
In the space below draw how the flag would look in the different colours of light.
a) Red lightb) Green lightc) Blue light.
Complete the following.
All sounds are caused by ______. Sounds travel through ______, ______, and ______but not through a ______.
The ______the wavelength of the sound the higher the frequency of the sound.
The larger the amplitude of the wave the ______the sound.
The lowest frequency a human can hear is _____ Hertz
The highest frequency a human can hear is ______Hertz
Forces and their effects (Summary)
Your teacher will take you to an ICT room to complete the following activity using a boardworks presentation “Forces and their effects”
1)A force is a ______, ______or ______.
2)Complete the following table to show each type of force
Push / Pull / TwistWriting on paper
3)Copy the diagrams and show which direction the ball will travel. The first one is done for you.
4)Complete the sentences
Mass is ______.
Weight is ______.
5)Why can an astronaught jump higher on the moon than he can on the Earth?
______
6)Does the mass of the astronaught get lower when he goes to the Moon?
______
7)A Scientist would say a boy had a ______of 50kg or a ______of 500 N.
8)When forces are ______an object remains stationary.
9)When forces are ______an object will accelerate.
10)What is friction? ______
______
11)Label all of the sources of friction on the diagram below.
12)Copy and complete the following diagrams to show the resultant forces.
13)What is Thrust? ______
14)What is Up thrust? ______
15)Label all of the forces acting upon the fish and the boat.
16)The ferry arrives at Calais and is loaded with travellers.
What happens to the weight of the ship? ______
What happens to the up thrust on the ship? ______
Which is the largest, weight or up thrust? ______
End of unit summary
Light travels in ……………………… …...... Light can travel through
t...... objects but not through o...... objects.
One diagram below shows transmission of light . The other shows absorption of light. Copy the diagram. Use the words
transmission or absorption to label the diagram
Reflection
Light rays are scattered by rough surfaces and so a r……………………..cannot be seen.
A p…………………mirror is a flat mirror. Light is r……………………………..evenly by ap ……………………..mirror.
The angle of i...... = the angle of r......
Label the diagram showing reflection.
Refraction
Refraction takes place at the ...... between two
substances. For example, when light enters glass it ......
...... and bends ...... the n...... When it
leaves the glass it ...again and ...... from the n
Colour
White light is a mixture of colours. It can be split up using a p……………..to give a s of seven different colours. (r……………………………………………,o………………………….,………………………….………,…………………………………..,…………………………………..,…………………………………..,…………………………………….
This is called d......
Label the diagram below.
Filters
A red filters lets through ...... light but a...... all other colours.
We see objects as they only reflect some c......
W...... coloured objects reflect all the colours
A green object r...... green light but a...... the other colours.
B...... objects absorb all colours.
Forces Summary sheet
Forces and their effects
Forces are pushes or p………………. .
Forces can:
Change the s………..….…. or size of an object
Change the s…….……..... things are moving (make them move f……………….. or s……………..……)
Change the d…………...……. of a moving object
The unit for measuring force is the N …………………………. (N)
F………………….. is a kind of force cause by two things rubbing.
A….. resistance and w…………. resistance are kinds of friction . They are sometimes called d………….. .
U……………. pushes things up.
Things float in water because of u…………………….. .
Contact forces need to touch the thing they are affecting. Examples of contact forces are :
f…………………………
u………………………….
Non contact forces do not need to touch the thing they are affecting. Examples of non contact forces are :
m…………………………….
g…………………………….
s………………………….. e…………………………..
Balanced Forces
If you are floating in a swimming pool, your w…………… and the u……………. are balanced.
Label the forces on the diagram .
Friction
Friction can:
s……………………..things down eg……………………………………….
w…………. things away eg…………………………………………………
produce h…………… eg………………………………………………………
produce s………………..eg …………………………………………………….
Friction can be helpful, for instance;
- Your shoes g…. the floor because of friction
- Tyres and b…….. in cars use f…………….
- Striking matches
Friction is not always wanted:
- Parts of engines wear away because of friction
- Friction make bicycles h……………….. to pedal
Friction can be increased by using r……………. surfaces, or by using materials like rubber.
Friction can be decreased by using smooth surfaces or by l……………………………………. Things like o……. and grease are lubricants.
Explain what this formula means:-
Pressure = force area
Units of pressure are ……………………………….
What does the moment (or turning force) depend on?