BỘ LUYỆN NGHE TIẾNG ANH 8 GLOBAL SUCCESS CẢ NĂM (GỒM 12 UNITS, MỖI UNIT GỒM 3...
Y8-3-Force-Lesson-1-to-5.pdf
1. Animated Science
2018
KS3 Physics
Forces and Pressure
1 Forces and Motion 2 Electricity 3 Waves 4 Energy
5 Solid Liquids Gases 6 Magnetism 7 Radioactivity 8 Astrophysics
Topics….
• Lesson 1: Contact and Non-Contact Forces
• Lesson 2: Hookes Law
• Lesson 3: Friction and Air Resistance
• Lesson 4: Resultant Forces and Equilibrium
• Lesson 5: Work Done
2. Term Definition
acceleration Getting faster
gradient Slope on a graph
Extension When something gets longer
Air
resistance/
Drag
Friction caused by movement through
the air
Velocity Speed in a direction
Friction
Two surfaces interlock on a microscopic
level with ridges and crevices
Gravitational
field
The field that causes weight
Density mass/volume
turbulence Caused by shape of an object
Weight Force you feel due to gravity
Work Done
Force x distance = Work Done or the
energy input into a system
Hookes Law
For a spring the extension is proportional
to the weight added
Contact
Force
Forces where objects touch such as
friction
Non-contact
Force
Electrostatic, Gravitational, Magnetic
which does not require surface contact
and may pass through space.
3 Forces and Pressure – Key Terms
Term Definition
acceleration Getting faster
gradient Slope on a graph
Extension When something gets longer
Air
resistance/
Drag
Friction caused by movement through
the air
Velocity Speed in a direction
Friction
Two surfaces interlock on a microscopic
level with ridges and crevices
Gravitational
field
The field that causes weight
Density mass/volume
turbulence Caused by shape of an object
Weight Force you feel due to gravity
Work Done
Force x distance = Work Done or the
energy input into a system
Hookes Law
For a spring the extension is proportional
to the weight added
Contact
Force
Forces where objects touch such as
friction
Non-contact
Force
Electrostatic, Gravitational, Magnetic
which does not require surface contact
and may pass through space.
3 Forces and Pressure – Key Terms
3. Term Definition
acceleration Getting faster
gradient Slope on a graph
Extension When something gets longer
Air resistance/ Drag Friction caused by movement through the air
Velocity Speed in a direction
Friction
Two surfaces interlock on a microscopic level with ridges and
crevices
Gravitational field The field that causes weight
Density mass/volume
turbulence Caused by shape of an object
Weight Force you feel due to gravity
Work Done Force x distance = Work Done or the energy input into a system
Hookes Law For a spring the extension is proportional to the weight added
Contact Force Forces where objects touch such as friction
Non-contact Force
Electrostatic, Gravitational, Magnetic which does not require
surface contact and may pass through space.
3 Forces and Pressure – Key Terms
4. Animated
Science
2018
Mr D Powell
2018
Animated Science
2018
D/E
B
C
Lesson 1: Contact and Non-Contact Forces
I can identify a range of forces.
++explain the difference between contact
and non-contact forces. Draw free body
diagrams
+categorise forces based on their
interaction.
+++ explain the idea of fields causing forces?
Key Ideas…. To develop an understanding of
contact and non-contact forces.
5. Animated Science
2018
Forces and Representing Forces
Friction is a CONTACT force, the surfaces have to touch
for the force to have an effect.
Some forces exist where contact is not necessary;
Electrostatic forces – running water being
attracted to a charged plastic rod.
Magnetism – a magnet attracting paper clips
Gravitational pull – an apple falling on your head or can cause
friction
6. Animated Science
2018
Lesson 1: Contact and Non-Contact Forces – Practical Sheet
Observations + Forces Free body Diagram (pencil) inc Arrows (ruler use) to scale if possible
Magnetic Field: magnet and iron block Frictional Forces: your shoe
Friction: Wooden block pulled with string or similar… Electrostatic Forces: balloon and paper OR ruler and water
Upthrust: bowl of water and ping pong ball Gravity: Dropping a beanbag or similar
Complete the Practical here OR write out the findings direct into your book…
7. Animated Science
2018
Lesson 1: Contact and Non-Contact Forces – Instructions
Observations + Forces Free body
Diagram (pencil) inc Arrows (ruler use)
to scale if possible
Magnetic Field:
magnet and iron
block
Frictional Forces:
your shoe
Friction: Wooden
block pulled with
string or similar…
Electrostatic
Forces: balloon and
paper OR ruler and
water
Upthrust: bowl of
water and ping
pong ball
Gravity: Dropping a
beanbag or similar
Complete the Practical round robin AND write out the findings
direct into your book…
W
S
8. Animated Science
2018
Lesson 1: Forces and Representing Forces
0
0.5
1
1.5
2
2.5
Floor Desk Carpet Plastic
Force
in
Newtons
(N)
Average Frictional Forces
between a shoe and the
surface
Electrostatic
W
R = Resultant
W
S
Support / Normal Reaction
Pull
Friction
W
Magnetic
W
Upthrust
U = W
W
Drag
Drag = W
(mid flight)
Electrostatic
Weight
10. Animated Science
2018
Do Now Task....
1 3
2
On a whiteboard in a pair, discuss
and write a quick summary of your
understanding of…
1. How you would measure the
extension of a spring when a
mass is added
2. How you can obtain data to
prove a relationship for the
stiffness of spring
3. What sort of graph you might
plot?
Where did you get
to on this idea?
11. Animated
Science
2018
Mr D Powell
2018
Animated Science
2018
D/E
B
C
Lesson 2 Hookes Law
I can identify Hooke’s Law
++analyse Hooke’s Law data to provide a
simple conclusion
+experimentally test Hooke’s law
+++ I can explain in detail the idea of proportionality and
use a graph to give weight to my arguments.
Key Ideas…. To develop an understanding of Hooke’s Law
12. Animated Science
2018
Making a Prediction….
0
10
20
30
0 5 10
Extension
/cm Weight Added /N
0
10
20
30
0 5 10
Extension
/cm
Weight Added /N
0
10
20
30
0 5 10
Extension
/cm
Weight Added /N
0
10
20
30
0 5 10
Extension
/cm
Weight Added /N
A
B
C
D
Task:
With your partner
who you will do the
practical with try
and come up with a
prediction for what
you think will
happen when the
spring extends?
You can use the
graphs to help you.
Write it down on
your sheet and try
and justify why?
Discuss in a pair
13. Animated Science
2018
Setup….
F = kx
F, is the force in Newtons, N
k, is the spring constant in Newtons per metre, N/m
x, is the extension in metres, m
AVOID THIS with
to much mass!
14. Animated Science
2018
Lesson 2: Hookes Law
Weight
/
Length /
loading unloading Mean
I predict that the graph that shows the relationship
between the Weights added and Spring Stiffness is
Graph …………………………………….
This is because ……………………………………………………………
…………………………………………………………………………………….
…………………………………………………………………………………….
…………………………………………………………………………………….
…………………………………………………………………………………….
Conclusions ……………………………………………………………………………………………….
…………………………………………………………………………………………………………………..
…………………………………………………………………………………………………………………..
…………………………………………………………………………………………………………………..
…………………………………………………………………………………………………………………..
…………………………………………………………………………………………………………………..
15. Animated Science
2018
Lesson 2: Stretching and Squashing (Extra Help)
Weight
(N)
Length (cm)
loading unloading Mean
0 0 0 0
2 2.1 1.9 2
4 4.1 3.9 4
6 6.2 5.9 6
8 8.1 7.9 8
10 13 13 13
12 20 20 20
Conclusions ……………………………………………………………………………………………….
…………………………………………………………………………………………………………………..
…………………………………………………………………………………………………………………..
…………………………………………………………………………………………………………………..
…………………………………………………………………………………………………………………..
…………………………………………………………………………………………………………………..
0
5
10
15
20
25
0 5 10
Length
/cm Weight Added /N
I predict that the graph that shows the relationship
between the Weights added and Spring Stiffness is
Graph …………………………………….
This is because ……………………………………………………………
…………………………………………………………………………………….
…………………………………………………………………………………….
…………………………………………………………………………………….
…………………………………………………………………………………….
16. Animated Science
2018
0
5
10
15
20
25
0 2 4 6 8 10 12 14
Length
/cm
Weight Added /N
This part obeys
Hooke’s Law. This
means that if I
increase the Weight
by the same
amount each time.
The increase in
length is
proportional.
When I unload the
spring it returns to
it’s original length.
Example Results….
This part is where it
plastically deforms
so it is permanently
stretched.
Weight (N) Length (cm)
0 0
2 2
4 4
6 6
8 8
10 13
12 20
17. Animated Science
2018
0
5
10
15
20
25
0 2 4 6 8 10 12 14
Length
/cm
Weight Added /N
This part obeys
Hooke’s Law. This
means that if I
increase the Weight
by the same
amount each time.
The increase in
length is
proportional.
When I unload the
spring it returns to
it’s original length.
Extra Help to Explain….
This part is
where it
plastically
deforms so it
is permanently
stretched.
Weight
(N)
Length (cm)
Exp 1 Exp 2
0 0 1
2 2 2
4 4 3
6 6 4
8 8 5
10 13 6
12 20 7
X
X
X
X
X
X
X
19. Animated Science
2018
Conclusion help….
This part obeys Hooke’s
Law.
This part is where it
plastically deforms
it is permanently
stretched.
I increase the Weight by the
same amount each time.
The increase in length
is proportional
When I unload the spring
it returns to the original
length.
After a plastic deformation
the spring does not return
back to its original length
Task: If you need some help, use some
of these ideas in your own conclusion.
DON’T just copy them off the board in
a random order!
20. Animated Science
2018
This part obeys
Hooke’s Law.
This part is where
it plastically
deforms
it is
permanently
stretched.
I increase the
Weight by the
same amount each
time.
The increase in
length is
proportional
When I unload
the spring it
returns to the
original length.
After a plastic
deformation the
spring does not
return back to its
original length
Instructions: Cut out the statements, glue
around the small graph to explain it…
Conclusion help….
This part obeys
Hooke’s Law.
This part is where
it plastically
deforms
it is
permanently
stretched.
I increase the
Weight by the
same amount each
time.
The increase in
length is
proportional
When I unload
the spring it
returns to the
original length.
After a plastic
deformation the
spring does not
return back to its
original length
Instructions: Cut out the statements, glue
around the small graph to explain it…
Conclusion help….
23. Animated Science
2018
Structured Review Questions
Weight
(N)
Full length of
spring (i) + (ii)
(cm)
Length (ii)
(cm)
0 30 0
2 32 2
4 34 4
6 36 6
8 38 8
10 43 13
12 50 20
a Look at the diagram. What do we call the two lengths, (i) and (ii)? [2]
b Copy and complete the table by calculating the values of length
(ii).
[3]
c Draw a scatter plot of the values of length (ii) on X on Y-axis and
Weight on X - axis
Draw a line of best fit.
[5]
d State Hooke’s law and explain how the graph demonstrates the
law.
[4]
24. Animated Science
2018
Structured Questions
Weight
(N)
Full length of
spring (i) + (ii)
(cm)
Length (ii)
(cm)
0 30
2 32
4 34
6 36
8 38
10 43
12 50
a Look at the diagram. What do we call the two lengths, (i) and (ii)? [2]
b Copy and complete the table by calculating the values of length
(ii).
[3]
c Draw a scatter plot of the values of length (ii).
Draw a line of best fit.
[5]
d State Hooke’s law and explain how the graph demonstrates the
law.
[4]
25. Animated Science
2018
Answers...
Weight (N) Full length of spring
(i) + (ii) (cm)
Length (ii)
(cm)
0 30 0
2 32 2
4 34 4
6 36 6
8 38 8
10 43 13
12 50 20
a) Length (i) is the original length.
Length (ii) is the extension.
2
3
d Hooke’s law states that the extension of a spring is proportional to
the force producing it, providing that the elastic limit is not exceeded. (2)
The straight-line section of the graph shows extension proportional
to force. (1)
The bent section shows where the elastic limit has been exceeded. (1)
26. Animated Science
2018
0
5
10
15
20
25
0 2 4 6 8 10 12 14
Length
/cm
Weight Added /N
Look at your graph… (answer the questions in your book)
1. What does this mean
2. Can you explain any of the features?
3. Can you work out an extension of a spring from experimental
data for a given force
4. Work out the potential energy stored in a stretched spring
using the formula Ep = 0.5Fx for a point on the graph (x in m)
Plenary OR
Review
Task…
27. Animated Science
2018
Example…. To Find “k” – extension!
y = 22.718x
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
0 0.1 0.2 0.3
Force
Added
/N
Extension /m
Weight in N
Extension of
spring /m
Force/ N
0.00 0.0
0.04 1.0
0.09 2.0
0.14 3.0
0.18 4.0
0.22 5.0
0.26 6.0
The Spring constant:
grad = ∆F/ ∆x
grad = 4.4N / 0.21m
k = 21Nm-1
∆F = F2-F1
= (5.7-1.0)N
= 4.4N
∆x = x2-x1
= (0.25-0.04)N = 0.21N
28. Animated Science
2018
Starter 1....
Why do surfaces feel friction….
Zoom!
?????
The old/modern car will use the least
petrol because……
Streamlining Air Resistance Force Smooth Rough Shape
Starter 2....
29. Animated
Science
2018
Mr D Powell
2018
Animated Science
2018
D/E
B
C
Lesson 3 Friction and Air Resistance
I can define friction
++ analyse the factors that have the
biggest effect on friction
+ experimentally determine the
factors that affect friction
+++ explain in detail ideas of “turbulence” and “clean air”
Key Ideas…. To develop an understanding of
friction and air resistance
30. Animated Science
2018
Streamlining In class…. (27 mins)
Task…
1. Discuss the movie you
have seen?
2. What are your thoughts
on air resistance?
3. Can you explain what
happens in each case?
31. Animated Science
2018
Streamlining at home…. (3 mins)
Task…
1. Discuss the movie you
have seen…
https://youtu.be/5AJVlt6
o6Yc
2. What are your thoughts
on friction OR air
resistance?
3. Can you explain what
happens in each picture?
4. Make some notes of
your own.
32. Animated Science
2018
One more? Probably the
most important…
tyre and road
brake pad and
rim
wheel bearing
wheel
bearing
pedal bearing
links in chain
Air resistance or “Drag”
Frictional Forces on a Bike – Where are they?
33. Animated Science
2018
Lesson 3 Friction and Air Resistance
A student dragged a block of wood across the desk with a
material glued to the lower surface varying the amount of
downwards force. The results are shown below….
1) Draw a LOBF for the material shown (pencil) (2)
2) Complete the other materials and create your own
legend so they are clearly identified. (points = 2, LOBF = 2,
legend or key = 1)
3) Compare each surface when the weight is 5N, what are
the frictional forces for each one? (3)
4) What is the range of frictional force for the Al? (1 mark)
5) Think about how the surfaces relate to each other and
the desk. Draw a simple diagram in your book to show how
they might be different using interlocking theory. Write a
suitable conclusion for the practical. (4 marks)
Total Weight /N
Frictional Forces /N
Rubber Brush Mat Al Sheet
2.0 1.8 0.8 0.6
3.0 2.5 1.2 0.8
4.0 3.4 1.6 1.0
5.0 4.6 2.0 1.4
6.0 5.3 2.4 1.8
7.0 6.3 3.0 2.2
8.0 7.2 3.6 2.4
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
0.0 2.0 4.0 6.0 8.0
Frictional
Forces
/N
Total Weight/ N
34. Animated Science
2018
Answers…. Total / 15
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
0.0 2.0 4.0 6.0 8.0
Frictional
Forces
/N
Total Weight/ N
Linear (Rubber)
Linear (Brush Mat)
Linear (Al Sheet)
1) LOBF (1) with (pencil) (1)
2) Complete the other materials
and create your own legend so
they are clearly identified.
(points = 2, LOBF = 2, legend = 1)
3) Compare each surface when
the weight is 5N, what are the
frictional forces for each one? (3)
Al: 1.4N / BM: 2.0N / Rub: 4.6N
4) What is the range of frictional
force for the Al? (1 mark) 1.8N
OR 0.6N to 2.4N
5) Clearly shown interlocking
diagram + Conclusion F ∝ W for
each Rubber grips most (2 marks
+ 2 marks)
36. Animated Science
2018
Interlocking Theory Diagram Examples…
Friction always tries to slow moving objects
down. It makes things hard to move and gives
things ‘grip’. Sometimes this can be useful,
sometimes it is not.
Oil or grease acts as a lubricant, it fills the
‘ridges and valleys’ of the surface (when looked
at under a microscope). This means the
surfaces can move smoothly over one another,
without interlocking.
37. Animated
Science
2018
Mr D Powell
2018
Animated Science
2018
D/E
B
C
Lesson 4: Resultant Forces and Equilibrium
I can identify a range of
forces AND resultant
forces
++ resolve resultant forces in four
directions.
+ describe and resolve resultant forces in
two directions.
++ work out an unknown force in a balance situation.
Key Ideas…. To develop an understanding of resultant forces
and equilibrium
38. Animated Science
2018
Prep Task 1….
https://www.youtube.com/watch?v=YGGxf6cp3Lo
Task…
Make notes on
the video –
draw the
images and
arrows carefully
39. Animated Science
2018
Prep Task 2….
Task…
Make notes on
the video –
draw the
images and
arrows carefully
https://www.youtube.com/watch?v=22VGQM1jCn8
40. Animated Science
2018
Lesson 4: Resultant Forces and Equilibrium
Task: For each situation write quick answer, to how the resultant is worked out and what it is?
1 2
3
4
5
44. Animated Science
2018
Answers.....
Since the anticlockwise moment = clockwise moment, seesaw is balanced.
Clockwise moment = 40 N × 1.8 m = 72 Nm
Since the seesaw is balanced, anticlockwise moment = clockwise moment.
Anticlockwise moment = 72 Nm = F ×0.8 m
F = 72 Nm ÷ 0.8 m = 90 N
45. Animated Science
2018
What about here on a see-saw?
Anticlockwise moment = 20 x 12 = 240 Nm
Clockwise moment = 8x F
8 x F = 240
F = 30 N
46. Animated Science
2018
Plenary / Review Task…
Where did you get to today and be
prepared to justify your answer!
On a whiteboard or in your books in a pair, discuss and draw free body
diagram such as these shown.
Use your own forces arrows and show the resultant and what happens
to it!
2 simple arrows and a resultant at 180°
4 arrows and a resultant at 180° & 90 °
6 or 8 arrows and a resultant at 180° & 90 °
and diagonal motion!
48. Animated
Science
2018
Mr D Powell
2018
Animated Science
2018
D/E
B
C
Lesson 5: Work Done
I can define work done
and it’s units
++ rearrange the work done
equation AND use in
questions
+ calculate work done
using the equation
+++ link ideas of work done on a flat surface to work done
against a gravitational field.
Key Ideas…. To develop an understanding of work done and how
to calculate it
49. Animated Science
2018
Work is the energy transfer that takes place when a force causes an object to
move.
work done = force applied × distance moved in direction of force
What is crucially important is to realise that no energy transfer takes place (in
that direction) when the motion is not in the direction of the force!
work done is measured in joules (J)
force is measured in Newtons (N)
distance is measured in metres (m)
100N W = Fd
= 100N x 5m
= 500Nm
= 500J
5m
Work Done…. (Make a note of this key idea)
50. Animated Science
2018
Introduction to “Work Done” - Eureka! Episode 8 - Work
Using the video discuss these questions with a
partner / use a whiteboard to record the
answers;
1. What is the difference between mass and
weight? (re-cap)
2. What do we mean by the term “work”?
3. Give an example with diagram (with maths
of work done relating to lifting a weight.
4. Now give a 2nd example but when the work
done is in a horizontal direction?
5. Give an example of when work is not
done?
6. Define the Joule.
51. Animated Science
2018
Work Done Practical… 10mins
Work with a partner to investigate work done.
Equipment…
• 1kg mass
• 0.5kg mass
• Ruler
• 1-10 Newton meter
Steps….
1. Draw out an example cartoon where you
move an object i.e. the masses
2. Label the variables on the cartoon
3. Write out your calculation WAU.
4. Try another!
?
52. Animated Science
2018
Intro: “Work Done” Eureka! Episode 8 - Work
Using the video discuss these questions with a partner / use a
whiteboard OR your book to record the answers;
1. What is the difference between mass and weight? (re-
cap)
2. What do we mean by the term “work”?
3. Give an example with diagram (with maths of work
done relating to lifting a weight).
4. Now give a 2nd example but when the work done is in a
horizontal direction?
5. Give an example of when work is not done?
6. Define the Joule.
Consolidation Questions….
1. When I move an apple
(1N weight) a distance
of 2m along a desk
what is the work done?
2. When I move 0.5kg a
distance of 3m along a
desk what is the work
done?
Challenge Question…
When a weight lifter lifts a
weight of 80kg a height of
1.5m what is the work done?
(mg∆h)
Intro: “Work Done” Eureka! Episode 8 - Work
Using the video discuss these questions with a partner / use a
whiteboard OR your book to record the answers;
1. What is the difference between mass and weight? (re-
cap)
2. What do we mean by the term “work”?
3. Give an example with diagram (with maths of work
done relating to lifting a weight).
4. Now give a 2nd example but when the work done is in a
horizontal direction?
5. Give an example of when work is not done?
6. Define the Joule.
Consolidation Questions….
1. When I move an apple
(1N weight) a distance
of 2m along a desk
what is the work done?
2. When I move 0.5kg a
distance of 3m along a
desk what is the work
done?
Challenge Question…
When a weight lifter lifts a
weight of 80kg a height of
1.5m what is the work done?
(mg∆h)
53. Animated Science
2018
Video Task….
Task…
Watch the two short videos.
Make notes on the key ideas in
your book.
Draw the images and arrows
carefully
https://youtu.be/yjUsfG_UvZE
https://youtu.be/nQI9z79UmT4
54. Animated Science
2018
Consolidation Questions….
1. When I move an apple (1N weight) a distance of 2m along a desk
what is the work done?
2. When I move 0.5kg a distance of 3m along a desk what is the
work done?
3. When a weight lifter lifts a weight of 80kg a height of 1.5m what
is the work done? (mg∆h)
1. 2J
2. 15J
3. 1200J
55. Animated Science
2018
Structured Questions “Forces” Review….
1
Forces can involve pushes, pulls or turning. Forces appear whenever two
objects interact.
1a
Give two different examples each of pushing forces and pulling
forces.
[4]
1b
Describe the two forces involved when a large, heavy box rests
on a flat floor.
[2]
1c Explain why the box, if it is left alone, does not move. [3]
1d
What other forces appear if you try to move the box across the
floor? (Harder)
[3]
1e
Explain how a lubricant such as oil, can make the box easier to
slide across the floor. (Harder)
[4]
56. Animated Science
2018
Structured Answers “Forces” Review….
M Level
1a Any two sensible answers for pushing, and two for pulling. Some examples are as follows:
• Pushing – shark pushing its teeth into prey, chair pushing up on you when you sit
down, person pushing a box.
• Pulling – a magnet pulling a piece of steel, the Sun’s gravity pulling on Earth, a horse
pulling a cart.
4 3
1b Gravity pulls down on the floor causing wgth and the floor pushes up on the box (Support) 2 4
1c The push of the box on the floor is exactly the same as the push of the floor on the box.
There are no other forces on the box, so it does not move. 3 5
1d The force of you pushing on the box makes it move. The force of friction from the floor
pushes back on the box. 3 6
1e In their answers students should be making connections between forces, the properties of
liquids, and pressure.
• Friction is caused by the interaction (roughness) of surfaces.
• The weight of the box causes the surfaces to be pushed into each other increasing the
interaction and making the box more difficult to slide.
• Particles in solids cannot easily move.
• The lubricant separates the surfaces by forming a layer in between them.
• The particles in a liquid can move past each other easily and so a smaller force is
required.
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