Gunter Primary School - Year 4 - Forces and Friction
Children build on their knowledge of forces & learn that forces can be measured & compared.
The unit focuses mainly on friction as a force which exists between objects moving across
solid surfaces & opposes motion, & the forces of air resistance & water resistance which
oppose the motion of objects moving through air & water.
EXPECTATIONS - at the end of this unit
most children will:
describe some factors that increase friction between solid
surfaces & increase air & water resistance; describe how to
measure forces & describe how to investigate friction,
explaining what their results show & relating what they found
to their everyday experience
some children will not have
identify friction as a force; describe some ways in which
made so much progress and friction between solid surfaces can be increased and identify
will:
some trends or patterns in observations and measurements
some children will have
describe situations in which frictional forces are helpful as well
progressed further & will also: as those in which frictional forces resist motion
Key objectives for term 1b
1. Deciding what evidence should be collected when planning and carrying out a fair test
2. Make measurements using a forcemeter
3. Look for patterns in results, interpreting and suggesting explanations for these.
Forces and Friction
Lesson / Session
Keywords
Key Objectives
Children should
Learn:
Main
Activity(ies)
Lesson 1
Force.
Magnet. Attract / Repel. Pole, north / south.
Metals, iron, steel. Materials
That a magnet has ‘poles’ - that opposite poles attract, same poles repel.
That only iron or steel are attracted to a magnet.
To devise a simple test following a set pattern.
Review learning by asking questions to elicit ideas about forces they have
already encountered e.g. pushes & pulls, exemplified by attraction &
repulsion between magnets, stretched & compressed springs; forces
acting on objects in particular directions; effects of forces in relation to
their size.
Reinforce by letting children explore magnets & springs, asking them to
identify the directions in which the forces are acting.
Recap on magnets – grid
N
S
N
Repel
Attract
S
Attract
Repel
Children to experiment to show that iron and steel are attracted – other
materials available are not.
Carry out simple experiment to show and compare strength of magnets.
Follow a set pattern to answer questions – children to suggest own ideas
– different ideas to be used in small groups [e.g.. How many paper clips in
a chain can hang down? Distance that a paper clip can be attracted? How
many pages will a magnet work through to attract a paper clip?
Follow planning sheet for Year 4. Emphasis in experiments in recording
results to compare.
Write up and illustrate work carried out
Differentiation
Special
Resources
Success
Criteria
Cross
Curricular
Activities
Low – directed to test strength by hanging paper clips. Shown how to
construct a simple results chart. Work with TA as group.
Middle / high – examples of how to set out results given.
Large variety of magnets
Named metal samples and other materials
Springs
Science plan / record sheet for Y4
The children will be able to talk about which poles are attracted / repelled
– which metals are attracted to a magnet (and NOT answer METAL).
They will know that pushes and pulls are associated with forces.
Mathematics – measurements.
Forces and Friction
Lesson / Session
Keywords
Lesson 2
forcemeter, newtons
push, pull
Key Objectives
Children should
Learn:
Main
Activity(ies)
- to use a forcemeter carefully to measure forces
- that ‘newton’ is the unit of force
1. Show children forcemeters and ask them to suggest how they work.
Help children to practise reading the scale on forcemeters.
2. Demonstrate that forces change. E.g. a door pushing at the outside of
the door or the inside requires very different amount of force to make the
door move. Talk about moving through water at the swimming baths. Ask
for children’s’ suggestions about how forces, pushes and pulls, vary in
everyday life.
Watch first 5 slides of ppt on friction.
3. Simple test about forces changing with a weighted box moving on slope
- flat - uphill - downhill (same surface).
4. Children to describe different situations where pushes / pulls are
different. Examples listed up / down hill - in / out of water / on a swing
with small / large person……
Illustrate with arrows to indicate stronger and weaker forces.
End with question about how different surfaces might affect forces.
Differentiation
Low – group work with TA and simple pictures showing pushes / pulls. To
describe what is happening in terms of push / pull.
Middle – record some different forces measured with forcemeter.
High – suggest how a forcemeter could be made using elastic bands to
measure pushes and pulls
Special
Resources
PPT - Friction
Elastic bands. Forcemeters.
Weighted box.
Success
Criteria
Have used a forcemeter to measure different forces.
Can describe everyday forces as pushes / pulls.
Can explain how a force varies in strength.
Cross
Curricular
Activities
Swimming – forces on body
Mathematics – reading scales
Forces and Friction
Lesson / Session
Keywords
Lesson 3 and 4
words & phrases relating to forces e.g. forcemeter, newtons, friction,
surfaces
Expressions making generalisations related to patterns in data.
Key Objectives
Children should
Learn:
- that there is a force between an object and a surface which may prevent
the object moving
- that the force between two moving surfaces in contact is called friction
Emphasis on objectives relating to experimentation:
*Decide what evidence to collect
*Predict what they think will happen
Plan a fair test
Make careful measurements
Main
Activity(ies)
Repeat q from last lesson - whether it would be more or less difficult to get
an object moving on a smooth or rough surface. Ask children how they
might answer this question &, if necessary, demonstrate using a
forcemeter attached to an object e.g. a weighted margarine tub, how this
question might be investigated.
Children to investigate on which surfaces objects slide most easily.
Present children with at least 3 different surfaces e.g. wood, vinyl, carpet
& ask them what they think will happen. Help to decide what to do
e.g. measuring the force needed just to start an object moving on a flat
surface or measuring the height of a slope on which it will start to slide &
how to ensure their test is fair e.g. keep the object to be moved identical
on each surface or by keeping the same surface.
Children to present results in a bar chart. Discuss the different methods
chosen to investigate the question, & whether some were better than
others for answering the question.
Differentiation
Low - TA guidance throughout to set up and carry out experiment. Group
recording of results by TA.
Middle – work through planning sheet 1 section at a time with teacher.
High – to explain details of their results to the class and suggest other
possible experiments to show friction.
Special
Resources
Weighted margarine tubs. Different surfaces. Long wooden plank
Forcemeters
Planning sheets
Know that friction is caused when 2 touching surfaces are moving
Have written out the experiment and related the results to a conclusion
Mathematics – recording results in a table.
Success
Criteria
Cross
Curricular
Activities
Forces and Friction
Lesson / Session
Keywords
Lesson 5
words & phrases relating to forces e.g. forcemeter, newtons, friction,
surfaces
Key Objectives
Children should
Learn:
- that there is a force between an object and a surface which may prevent
the object moving
- that the force between two moving surfaces in contact is called friction
- that friction may be useful (or not)
Main
Activity(ies)
Ask children to suggest what their work indicates about surfaces for
roads, if cars and bicycles are to be safe & not to slide.
Children to suggest in what other ways does friction affect us in everyday
life? E.g.. Grips are useful for….. when is friction not useful….
Use science reference books / Internet to look up more about friction.
Write up and illustrate discussions.
Differentiation
Low – word list and pictures supplied to be used as group exercise with
TA.
Middle – to use correct vocabulary about surfaces, friction and describe
strength of friction as low / high (+ suffixes)
High – extended examples provided and range of own ideas.
Special
Resources
Reference books.
Internet
Pictures showing ‘friction’
Success
Criteria
I can describe the affects of friction in different situations – including good
and bad effects.
Cross
Curricular
Activities
IT use of Internet
Forces and Friction
Lesson / Session
Keywords
Lesson 6
words & phrases relating to forces e.g. forcemeter, newtons, friction,
water resistance, surface area, Streamlined
expressions making generalisations related to patterns in data.
Key Objectives
Children should
Learn:
* that water resistance slows an object moving through water
* to explain what evidence is to be collected & decide if the test is fair
* to identify trends in results & draw conclusions explaining these in terms
of the force between the object & the water
Main
Activity(ies)
Children to describe what it is like to walk through water and suggest why
it is difficult. Elicit ideas about why fish & boats can move through water. If
necessary prompt about shape.
Show a tall cylinder filled with water & talk about what they could do, using
this apparatus & plasticine, to find out which shapes move easily through
water. Help to decide what to measure e.g. time from dropping the
plasticine into the cylinder until it gets to the bottom
Emphasis on how to make the test fair e.g. by always using the same
piece of plasticine made into different shapes, always using the same
height of water in the cylinder.
Children to record results in a table & interpret these in terms of the shape
of the object & water resistance. Discuss ideas.
Differentiation
Low – TA guidance throughout discussion and written work - children to
suggest and make own shapes for testing.
Middle – with teacher direction, complete planning and record sheet for
Y4
High – small group work using planning and record sheet to direct and
record work.
Special
Resources
Success
Criteria
Water containers. Plasticene.
Cross
Curricular
Activities
Swimming
Describe how they carried out a fair test
Identify which shapes move easily through water and explain this in terms
of reduction of resistance
Forces and Friction
Lesson / Session
Keywords
Lesson 7
words & phrases relating to forces e.g. forcemeter, newtons, friction, air
resistance, surface area
Expressions making generalisations related to patterns in data.
Key Objectives
Children should
Learn:
- that air resistance is a force that slows objects moving through air
- to identify a pattern in the results and to explain it in terms of air
resistance
Main
Activity(ies)
Take children outside & get them to run across the playground with /
without a large sheet of card held in front of them. Discuss what they can
feel & ask them to try to explain what is happening.
Extend the discussion to riding a bicycle into the wind or walking into the
wind on a windy day. Ask children to draw a picture to illustrate what is
happening & to annotate their picture to provide an explanation. Introduce
the term ‘air resistance’.
Demonstrate how the size of surface area affects how fast something falls
through air e.g. by using small pieces of cotton wool squashed up and
spread out.
Children to explain in terms of forces why you need to pull hard on a large
surface, e.g. a kite, an umbrella, a sail to hold it steady on a windy day
e.g. the air/wind is pushing the umbrella up so I have to pull hard to hold it
steady
Differentiation
Low – assistance with writing words as captions to pictures.
Middle / High – sentence explanations – can they think of their own
examples of air resistance?
Special
Resources
Large card sheet.
Kite
Umbrella
Success
Criteria
I can state that air resistance slows objects and show that I understand
this by giving an example.
Cross
Curricular
Activities
Possibly art / technology with design and make a kite – as time allows in
that subject.
Forces and Friction
Lesson / Session
Keywords
Lesson 8
words & phrases relating to forces e.g. forcemeter, newtons, friction, air
resistance, water resistance, surface area
Expressions making generalisations related to patterns in data.
Key Objectives
Children should
Learn:
- that air resistance is a force that slows objects moving through air
- to identify a pattern in the results and to explain it in terms of air
resistance
Main
Activity(ies)
Children to investigate parachutes – show pictures / ppt of parachutes in
action.
Question - does the size of a parachute affect how long it takes to fall?
Ask small groups what they plan to measure in order to answer the
question. When children have made and recorded some measurements
discuss them with the children and help them look for patterns in them.
Help children to relate this to their understanding of air resistance.
[In order to obtain satisfactory results with parachutes there needs to be
an adequate drop e.g. from the balcony in the hall].
Children to describe their fair test e.g. a square parachute with the same
weight each time & change size of the parachute
e.g. the largest
parachute took longest because it trapped most air which stopped it falling
quickly
Write up and illustrate experiments
Differentiation
Low – TA guidance throughout discussion and written work - children to
suggest and make own shapes for testing.
Middle – with teacher direction, complete planning and record sheet for
Y4
High – small group work using planning and record sheet to direct and
record work.
Special
Resources
Success
Criteria
Tissue paper for parachutes. Small plasticene weights. Cotton
Cross
Curricular
Activities
I can state that air resistance slows objects and show that I understand
this by giving an example.
I have recorded my results showing the difference in performance of the
parachutes
Forces and Friction
Lesson / Session
Keywords
Lesson 9
words & phrases relating to forces e.g. forcemeter, newtons, friction, air
resistance, water resistance, surface area
Expressions making generalisations related to patterns in data.
Key Objectives
Children should
Learn:
Main
Activity(ies)
Recap / Revise as required
Review work on friction by asking children to write and illustrate a story to
show how friction is important to them. Read and talk about the stories
with the children.
Complete unit review sheet
Differentiation
Low - TA assistance in completing written work
Middle / High – assessment of learning and effectiveness of the unit.
Special
Resources
Success
Criteria
None
Cross
Curricular
Activities
The children can
- Explain in simple terms what a force is
- describe the effect on forces of friction
- give examples of air and water resistance
/