6e: Forces in action

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6e Forces in action

• set 2

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Index
introduction safety lesson 1 Getting to know the
equipment homework task 1 lesson 2 Using a force
meter homework task 2 lesson 3 What are the
forces how do I draw them? lesson 4
Floating lesson 5 Scientific explanations lesson
6 Friction
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This is what you will be learning

• In this study unit you will be
• Building on what you learnt in years 3, 4 and 5.
• Learning about weight as a force.
• Learning what forces are.
• Learning how to measure forces.
• Learning how to draw diagrams to show forces.
• Learning how to accurately read a force meter.
• Drawing basic line graphs.
• Find patterns in results from experiments.
• Learning about a number of forces affect the way
  things move.

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By the end of this unit

• By the end of this study unit you should be able
  to
• Choose and use the right equipment for your
  investigations.
• Identify that weight is a force.
• Know that forces are usually measured in Newtons.
• Describe some situations where there are more
  than one force acting on an object.
• Draw diagrams to illustrate forces acting on an
  object.
• Use a force meter accurately to measure forces.
• Present measurements and results in simple line
  graphs.

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Safety

• Elastic bands can break and go into your eyes.
  WEAR GOGGLES.
• Never flick elastic bands at other people.
• Heavy weights can sometimes fall. KEEP YOUR HANDS
  AND FEET OUT OF THE WAY.
• Weights are heavy. DO NOT TRY TO LIFT TOO MUCH!

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Lesson 1

• Starting with some basics

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Objectives

• Check a few bits of basic learning.
• Learn to use drawings, one-word answers and short
  explanations.
• Learn how to describe what happens.

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Expectations

• You should be able to
• Use the equipment safely.
• Write and draw about your discoveries.
• Finish the assignment.
• Clear away efficiently.

SAFETY
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Teamwork
Work in pairs.
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Collect your equipment

• You will need
• Two different force meters. (Spring balances).
• Two identical magnets and several paper clips.
• A parachute.
• A whiteboard (between two)

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Instructions

• A) What would you measure with a force meter? ONE
  WORD ANSWER
• B) Explain why some force meters more accurate
  than others. SENTENCES
• C) How does the force meter work? DIAGRAM
• D) Why is force measured in NEWTONS?. SENTENCE
• E) In the wind tunnel, how does the size of the
  card on the trolley affect the drag force?
  SENTENCE
• F) Will two magnets put together pick up exactly
  twice as many paper clips as one? (yes or no)
• G) What happens when you put the ends of two
  magnets together? DRAWING
• I) What force slows the parachute as it falls?
  ONE WORD

These questions are in the study guide.
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Evaluation

• We helped each other to learn.
• We could use drawings to explain.
• We were good at the one-word answers.
• We tackled the explanation sentences.
• Our learning improved.

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Homework task 1
1. The Earth pulls everything downwards. What is
this downward pulling force called? 2. In
Britain, the Earth pulls everything downwards.
What happens in Australia? 3. The downward force
gives things weight. What units is the force
measured in?
Print homework slips x4
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Lesson 2

• Using a forcemeter

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Equipment
A variety of different objects to weigh A
selection of forcemeters Graph paper results
tables
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Objectives

• To learn to read a forcemeter accurately.
• To learn how to choose the right forcemeter for
  the job.
• To learn how to make a graph that shows results
  clearly.
• To learn about labels and captions on graphs.

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Expectations

• Work systematically to get accurate results.
• Present your results clearly in your book.
• Produce a graph that shows your results clearly.
• Add labels and captions to your graph.

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Part 1 Getting started
Work in pairs

• How much force does it take to make the elastic
  band double its length?

Results on mini-whiteboards.
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Part 2
Work in teams of four
(a) Weigh ten different objects using a force
meter. (b) Record your results on a table.
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Part 3

• What sort of graph would make your results really
  clear?
• Should there be gaps between the columns?
• Should you put the results in order?
• What label will you put on the x axis?
• What label will you put on the y axis?
• What will your caption be?

Now make a graph of your results.
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Homework task 2
Complete your graph.

• Think about what sort of graph would make your
  results really clear?
• Think about gaps between the columns?
• Decide whether you should put the results in
  order?
• Include a label on the x axis?
• Include a label on the y axis?
• Dont forget the caption to describe what your
  graph is about.

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Evaluation
Secret fist to five

• I can read most forcemeters accurately.
• I can choose the right forcemeter for the job.
• I know how to make a graph that shows my results
  clearly.
• I know how to do labels and captions on graphs.

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Lesson 3

• What are the forces and how do I draw them?

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Objectives

• Learn how to draw force diagrams.
• Learn how to mark forces on our drawings.
• Learn what the downward force is called.
• Learn how to label the forces.

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Expectations

• By the end of this lesson
• Take turns to draw diagrams on mini-whiteboards.
• Draw at least three force diagrams into your own
  book.
• Check what you know at the end of the lesson.

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First bit
Work in pairs Take turns to draw on the mini
whiteboard.
First drawing coming up
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What are the forces? 1.
Here is a weight hanging on a rubber band. Draw
it on your mini-whiteboard.
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What are the forces? 1.

• A weight hanging on a rubber band.

band
The force of gravity pulls downwards. Draw an
arrow.
The rubber band pulls upwards. Draw an arrow.
gravity
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What are the forces? 2.
magnetism

• A magnet attracting a paper clip.
• Draw the diagram.
• Add the arrows.
• Add the labels.

gravity
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What are the forces? 3.

• Floating magnets.
• Draw the diagram.
• Add the arrows.
• Add the labels.

magnetism
gravity
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What are the forces? 4.
spring in scales pushes up

• A packet on kitchen scales.
• You know what to do!

gravity
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What are the forces? 5.
upthrust

• A ball floating in water.
• Drawing, arrows and labels please.

gravity
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In your book
Draw at least three of the diagrams in your
book. Make sure each one shows the arrows and
the labels.
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Round-ups

• We know how to mark forces on our drawings.
• We know what the downward force is called.
• We know how to label the forces.

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LESSON 4

• Floating

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Equipment
mini whiteboards, pens erasers objects to weigh
in and out of water forcemeters jugs graph paper
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Starter
WORK IN PAIRS
What are the forces acting on this
aeroplane? Draw a diagram. Add the arrows. Add
the labels.
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OBJECTIVES

• Learn that forces can act in opposite directions.
• Learn about the force that makes things float.
• Learn to measure forces using a force meter.
• Revise that weight is a force measured in Newtons.

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By the end of this lesson

• Experiment and get some accurate results.
• Make a graph that shows your results very
  clearly.
• Write an explanation.

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First part
Float a ball in a jug of water. Try to push the
ball downwards. Can you feel it pushing up? What
is the upward force called?
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Experimenting
UPTHRUST or BUOYANCY, the force that makes things
float.
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Results

• You are going to make a graph of the UPTHRUST.
  Look back at the graphs page in your study guide.
  Which type of graph should you use?
• Hand-draw a graph of the upthrust results. Use
  graph paper or squared paper.

• Make an excel spreadsheet of the results. Can you
  use the formula function to automatically
  calculate the upthrust? Print the spreadsheet.
  Trim stick.
• Use Excel to make a graph of just the UPTHRUST
  column.

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Plenary Reaching a conclusion

• Use whiteboards in pairs.
• Why did all the objects weigh less in water?
• Report-back to class.
• Copy (redraft) conclusions to your book.

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Lesson 5

• Scientific explanations

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Equipment
Magnets, paper clips Plasticine (to make
boats) Cotton wool A4 scrap paper Mini
whiteboards, pens erasers
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Objective

• To learn how to write a good scientific
  explanation.

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By the end of the lesson

• You will have done 6 mini-activities.
• I will be able to see if you are now able to
  explain things clearly because there will be
  evidence in your book.

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After the demo - What makes a good explanation?

• The screwed up paper fell faster than the folded
  sheet.
• The flat sheet was slowest.
• Real parachutes are big so the person comes down
  slowly.
• Its because of air resistance.
• The large sheet trapped a lot of air, so there
  was a big force of air pushing up against
  gravity. This kept the sheet up longer.
• Air holds it up so it floats in the air.
• When there is no air, a coin and a feather fall
  at the same rate.

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Part 2 Trying scientific ideas

• Can you use a magnet to make a paper clip move
  without touching it? Write a sentence or two to
  explain how without using the word it.
• Can you make a lump of plasticine float. Show
  your teacher when you get success.
• Can you make a sheet of A4 paper fall as quickly
  as possible? Try different ways. The best way may
  not be obvious. Write a paragraph to explain how.
  What force were you trying to make as small as
  possible?
• Can you make a piece of cotton wool fall as
  slowly as possible? Write a paragraph to explain
  how. You must use the following words at least
  once drag, gravity, weight. Do not use the
  word it.
• Can you explain why roads have a surface that is
  rough, but not too rough?
• Can you draw a diagram to show the forces on a
  football as it goes through the air after being
  kicked?

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Rounding up

• The bit of the lesson I liked best was
• My new learning is
• I would like to know more about
• The thing I dont quite understand is
• Out of five, how confident are you about writing
  explanations?

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Lesson 6

• Friction

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Equipment
Equipment for Testing Trainers Old shoes,
forcemeters, 100g masses hangers. String, clamp
pulleys. Mini whiteboards, pens erasers.
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Objectives

• Learn that friction is a force that holds things
  back.
• Learn what friction is and how it happens.
• Learn to measure the effects of friction.

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and by the end of the lesson

• Be able to describe what causes friction.
• Be able to measure how much force it takes to
  overcome friction.

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Does friction make it hard to drag the shoe?
If you pull down on the string, you can measure
how much force it takes to start the shoe moving.
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Part 1 8 minutes to complete.

• Copy the diagram that is in the study guide.
• Draw a yellow force arrow on your diagram to show
  the force of gravity on the weights.
• Draw a blue arrow to show the force of gravity on
  the shoe.
• Friction is a force that grips and holds things
  back. Friction will make the shoe difficult to
  drag. Draw a green arrow to show the direction of
  the friction force.

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Part 2 20 minutes
Do the test record results.

• Some key question your teacher might ask
• Does the size of the shoe make a difference?
• Are you sure your test is fair?
• What factor makes the most difference to the
  friction?
• If the shoe is pulled forwards, what direction
  does the friction force act?

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Part 3 Rounding off your learning
Draft a short paragraph to explain why some shoes
were harder to pull than others. Try to include
your knowledge about what friction is. Some
groups will be asked to read their work to the
class.
work in pairs
Copy your paragraph (redraft) into your exercise
book.
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Lesson 8

• Finishing off

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Equipment

• Whiteboards, pens erasers.
• KS3 Levels 4 to 5 booklets.
• How am I doing? sheets.

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Objectives

• To help complete your learning.
• To establish what level you are working at.
• To establish what things you are doing well.
• To decide on some targets.

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Bookwork check list

• lesson 1 Getting to know the equipment
• homework task 1
• lesson 2 Using a force meter
• homework task 2
• lesson 3 What are the forces how do I draw
  them?
• lesson 4 Floating
• lesson 5 Scientific explanations
• lesson 6 Friction

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What are you doing well?
You can help each other to do this.
Make a list of two or three things that your
teacher says you are doing well.
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Now, what about some targets?
Look at your partners book. What things does the
teacher want improved? Choose two things and
write them on the whiteboard. Discuss your ideas.
Work in pairs

• Now redraft the targets onto your target sheet.