Yr 10 Forces and Motion 2015


pretest


Access Code
X86S5
Access Links
Test Link
http://www.classroomclipboard.com/490625/Test/34F5C4E538C7027703B0F361C77C62D8

Forces and Motion – key concepts Name: _
Key Concept
Vocabulary – Words To Learn


  1. 1. Relationships between force, mass and movement.
  2. 2. Energy changes are responsible for changes observed in motion and shape.
Distance and Displacement
Speed and Velocity
Acceleration and deceleration
Scalar and Vector quantities
Average and instantaneous
Standard International Units
Force
Friction
Air resistance
Lift thrust
Weight
Electrostatic
Magnetic
Inertia
Mass
Equilibrium/balance
Action/reaction
Gravity
Weightlessness
Terminal velocity
Kinetic Energy
Potential (stored) energy:
Gravitational & Elastic









Outcomes: To be able to:
Suggested Activities
Extension & Variation
1.
  1. 1. Use the formulae to calculate speed/velocity
  2. 2. Convert measurement units
  3. 3. Define average and instantaneous speed/velocity
  4. 4. Interpret data in graphical form
What do you know about forces? Read and complete the THINK activity and questions on page 261
Read 8.1 page 262-263 and answer Questions: 1-8

Interactive: Describing Movement, progress from the easy to the hard level
http://www.media.pearson.com.au/schools/cw/au_sch_rickard_sd4_1/dnd/sci4_5_1.html

Interactive: Understanding graphs answer the questions for distance and velocity by selecting the items on the top right of the screen.
http://www.media.pearson.com.au/schools/cw/au_sch_rickard_sd4_1/int/GraphMovement.html

Inquiry Investigation 8.1 Ticker Timer Tapes

Understanding and Inquiring Questions 1 and 2 page 266

Worksheets 8.1 and 8.2
A brief and amusing history of physics – a 4minute clip
http://gizmodo.com/a-brief-history-of-physics-1147115801

Interactive: Kinematics game: This is a kinematics’ game in which students are given a position - time or a velocity time graph, depending on level, and they have to set the initial position and velocity, and acceleration if needed and also, if needed, the time and value of any velocity or accel'n change. The game then draws out the graph from their set values and then identifies the sections of that graph that match the original graph.

http://theuniverseandmore2.blogspot.com.au/
2.
  1. 1. Define acceleration as speeding up or slowing down using directed numbers
  2. 2. Calculate the acceleration as Rate of change (of speed/velocity)
  3. 3. Understand and define acceleration due to gravity as an object goes up and down
Read 8.3 page 267-268 Questions: 1 – 3

Inquiry Drag Strips Investigation 8.2

Worksheet 8.3 Acceleration

3.
  1. 1. Define Newton’s 1st Law
  2. 2. Define Net Force on an object as the addition of all the forces on the object
  3. 3. Consider the vector nature of force
  4. 4. Draw a force on an object as a vector
Read 8.4 page 269-71 and answer Questions: 1 – 5 page 315

Prac: Experiencing Forces Booklet:
1.Types of Forces pages 3 - 4
2. Newton’s Ping Pong Balls pages 6-7
3. Circular Motion Page 8

Worksheets 8.4 and 8.5





4.
  1. 1. Define and use Newton’s 2nd Law for Net Force on an object parallel to the motion and understand the connection between net Force and mass
Read 8.5 page 272-273 and answer Questions: 1- 5 page 273

Inquiry investigation 8.4 Force, mass and acceleration

Worksheet 8.6

Interactive: Resultant Force
http://www.media.pearson.com.au/schools/cw/au_sch_rickard_sd4_1/int/forces.html

5.
  1. 1. Define Newton’s 3rd Law for action/reaction pairs of forces
  2. 2. Notate action/reaction forces in the form of Fa/b = - Fb/a
Read 8.6 page 274-275 and answer Questions: 1-6

Video: Collisions

interactive : Newton’s Laws
http://www.media.pearson.com.au/schools/cw/au_sch_rickard_sd4_1/dnd/sf4_0502.html
http://phet.colorado.edu/sims/collision-lab/collision-lab_en.html + worksheet
6.
  1. 1. To describe the safety features of modern cars
  2. 2. Use Physics to describe their function
The Reflex tester: http://www.bbc.co.uk/science/humanbody/sleep/sheep/reaction_version5.swf

Read 8.9 page 281-283 and answer questions 1-6, 7-9(in groups) page 283

7.
  1. 1. To understand the connection between the work done by a force on an object and the objects change of motion.
Extension work if there is time for classes or individual students.

Read 8.7 Page 276-277 and 8.8 page 278-280
Inquiry investigation 8.7 page 279

8.
Revision
Chapter Review Looking Back page 285

Test plus 1 A4 sheet, single sided, of summary notes

go to quizlet there are 3 revision games for you

https://quizlet.com/class/1688865/
Interactive crossword: http://wps.pearsoned.com.au/sd4/50/12994/3326638.cw/index.html




Class Notes 2015
Speed vs Velocity,,, Distance vs Displacement
1. Go for a walk and record where you went how far you wnet and how long it took to finally
Calculations and exploration
1. on a map of the school plot your travels
2.Record the number of steps
Record the time take
3 Use speed = distance / time to calculate you speed in m / s

4 a)How far from S5 did you go
b) How long did this take you?

Converting to metres per second

things to remember
1000m in 1 km
60 seconds in 1 min 60 min in 1 hr therefore there are 3600 seconds in 1 hour

to convert km / hr to m/s


step 1 change the km to m (eg km x 1000)
step 2 change hours to seconds (eg hr x 3600)
step 3 divide the answer from step 1 by the answer form step 2


OR as a short cut you can multiply m/s by 3.6 to get km/ hr

and divide km/hr by 3.6 to get m/s

USing Ticker Timers to describe motion
Make some ticker timer strips to show a constant speed - cut up a set of 3 strips of ticker paper that show 0.1s (ie 5 intervals ( 6 dots). Paste them in your book side by side. Label the vertical axis distance and the horizontal axis time.
Make a ticker timer strips to show speeding up (acceleration)
Make some ticker timer strips to show slowing down

SOme calculations

average speed = distance / time with this equation we need to watch the units -in a car our speed will be measured as km/hr, an athlete running may be measured in metres per second ie m/s

Velocity is speed in a certain direction. generaly in physics we measure in velocity in m/s. So if we have a problem in where data is provided as km/hr we will usually convert this to m/s. The reason we do this is to provide consistency when we measure other aspects of motion ( and we are following the SI units for physics)
To calculate velocity we measure the displacment (distance in a given direction) and divide by the seconds
velocity = displacement / time

When you used the ticker timers you were measuring distance and dividing by time to get the average speed for each little strip you cut up.
When you pasted each interval side by side you were making a distance tiime graph for that motion.

distance time graphs

distance time graph.png
Can you describe what is happening between each of the letters?In particular what is happening from C to D.What about B to CFrom A to B is a curve . A curve on a distance time graph shows acceleration.


velocity time graph.png
down load the complete pdf here it shows how to calculate acceleration




You should know how to describe the following on a distance time graph
1. standing still
2. travelling at a constant speed
3. accelerating
4. decelerating

Acceleration

WE describe acceleration as how quickly speed changes over a certain time. So if we start with a speed of 2m/s and increase that speed to 8m/s and it has taken 2 seconds to do this we say our acceleration is 3m/s/s
the calculation for this is acceleration = change in velocity (v -u) / time where v is the final velocity and u is the initial velocity.
Worked example
a bike starts at rest ( ie initial velocity is 0 m/s) and increases its velocity for 3 seconds to a final velocity of 12 m/s. Find the accelaeration

a = (v-u)/t
a = (12 - 0) / 3 ...............ie 12 / 3
a=4m/s/s

Positive acceleration -- is speeding up. eg when you press the accelerator you in crease your speed - this is acceleration.
Negative acceleration = deceleration = slowing down eg when you put the brakes on in a car - you are decelerating.


Newtons first law

a body will stay at rest ( or stay at the same veolcity (speed with direction)) until it is acted on by a force
general formula to find force acting on a body is
Force = mass x acceleration
F = ma the answer is in N ( Newtons)

Weight and potential energy and formula
One earth we have a weight force which can be calculated by

W=mass x acceleration due to gravity

W= mg acceleration due to gravity = 9.8m/s²

e.g. W= 70 x 9.8

W= 686 newtons = 686N
If we were on the moon acceleration due to gravity is 1.6/s/s therefor our weight force would be

W=70 x 1.6

W= 112 Newton’s or 112N

Newtons Second Law


Describes how a Force is created by a mass being accelerated or F = ma
In symbols, Newton's second law can be expressed as:
equation
equation

The net force is the total force acting on the object. If the net force is measured in newtons (N) and the mass is measured in kilograms (kg), the acceleration can be determined in metres per second squared (m/s2).

If a large force is applied to a small mass it will accelerate very fast eg you pushing a ball
If a large force is applied to a large mass it will accelerate slowly eg you pushing an elephant

In the last example you can imagine that elephant may want to push against you. the final direction and acceleration will depend on who has the largest push or force. The overall force is called the NET force. it always has direction.

If the net force is 0 we say the opposing forces are balanced - eg you sitting on a chair.

Newtons Third Law

Newton's Third Law of Motion states that for every action there is an equal and opposite reaction. That is, when an object applies a force to a second object, the second object applies an equal and opposite force to the first object.

eLesson

Newton's Laws


Learn about Newton's laws of motion and see them being applied in everyday life.
eles-0036
eles-0036
eles-0036
In fact, forces always occur in pairs. Sometimes it is painfully obvious. For example, when you catch a fast-moving softball or cricket ball with your bare hands, your hands apply a force to the ball. The ball applies an equal and opposite force to your hands — causing the pain.




Draw draw a person on a chair
how do the three laws work together


Work

8.7 Getting down to work
Work done on an object by a force is equal to the change in energy of the object.

Work is described as the amount of force required to move something a certain distance.
W = F x s where W = work and F = force and s = displacement or distance in a given direction.

Energy
The unit of energy is the Joule or J
Once something is moving we say it has Kinetic energy
and can calculate this by KE = 1/2mv x v 1/2 = half, m = mass, v = velocity

All stored energy is called potential energy. Energy can be stored in several different ways.
common calculation os of the amount of stored energy are

Potential Energy (PE) = mgh where m = mass, g = acceleration due to gravity (usually 9.8 m/s/s) and h is height off the ground in metres.
see below for worked examples
here are some other forms of stored energy.


  • Elastic potential energy (also called strain energy) is present in objects when they are stretched or compressed. Stretched rubber bands and springs have elastic potential energy. So do compressed springs like the one shown below. When the hand is opened, the elastic potential energy in the compressed spring is converted into kinetic energy.
  • Gravitational potential energy is present in objects that are in a position from which they could fall as a result of the force of gravity. The water in a hydro-electric dam has gravitational potential energy. When the water is released, the force of gravity pulls down on it, doing work and converting the gravitational potential energy into kinetic energy.
  • Electrical potential energy is present in objects or groups of objects in which positively and negatively charged particles are separated. It is also present when like electric charges are brought close together. The most obvious evidence of electrical potential energy is in clouds during thunderstorms. When enough electrical potential energy builds up, electrons move as lightning between clouds or to the ground.
  • Chemical potential energy is present in all substances as a result of the electrical forces that hold atoms together. When chemical reactions take place, the stored energy can be converted to other forms of energy or it can be transferred to other atoms. Chemical potential energy is a form of electrical potential energy.
  • Nuclear energy is the potential energy stored within the nucleus of all atoms. In radioactive substances, nuclear energy is naturally converted to other forms of energy. In nuclear reactions, such as those in nuclear power stations, in nuclear weapons and on the sun and other stars, nuclei are split or combine together. As a result, some of the energy stored in the reacting nuclei is converted into other forms of energy.

Energy efficiency

Efficiency = (the useful output / energy input) *100

eg Aball is dropped from 100cm it bounces up 40 cm.

The efficiency of the ball is mgh2/ mgh2




REview of formulae

Weight and potential energy and formula
One earth we have a weight force which can be calculated by

W=mass x acceleration due to gravity

W= mg acceleration due to gravity = 9.8m/s²

e.g. W= 70 x 9.8

W= 686 newtons = 686N
If we were on the moon acceleration due to gravity is 1.6/s/s therefor our weight force would be

W=70 x 1.6

W= 112 Newton’s or 112N
Energy and force
energy is neither created nor destroyed but it is transformed/

e.g. solar energy is transformed into electrical energy is transformed into moving energy
(a toy solar powered car or fan)

moving energy is called kinetic energy

kinetic energy = 1/2mv²
Find the KE of a car mass 1000kg moving at 10m/s
KE=1/2 x 1000 x 10
KE= 50000 joules or 50KJ

Gravitational potential energy (GPE)
GPE= mass x acceleration due to gravity x height (m)
E.g. find the GPE of a car of mass 1000 suspended 10m above the ground (g=9.8m/s/s)
GPE = 1000 x 9.8 x 10

GPE= 98000 joules or 98KJ

Key points
Newtons laws
first law - object stays at rest until acted on by a force
second law when a force acts on an object it will accelerate at a rate in proportion to the size of the force and the size of the mass it acts on F = ma
third law - For every force there is an equal and opposite reaction collisions forces exert equal and opposite. examples are collisions and inertia

Graphs Dist vs time graph ie dist / time
Distance / time = speed
a special case is a displacement time graph i.e. velocity = displacement / time
Big deal is displacment is distance with direction. This means displacement could be smaller than distance over the same journey eg if you went to the shops and got half way before you realised you forgot your purse and went back home and then went to the shops again. Displacement only looks at how far are you from your start ( home) While distance takes into account the return trip and back to the sshop
Velocity is speed in a given direction = this means overall velocity has to take into account the velocity back toward the starting point
speed vs time = tells us the acceleration

calculations ;
Hint how to do a physics problem
1 read the question and underline the data
2. draw a picture of what is happening
3. list the data required and the formula you might use - and convert to correct units
4. plug the data into the formula

acceleration = (final velocity – initial velocity) /times

a= (v-u)/t or v= u + at

example; find the final velocity of a giraffe with a mass of 500kg that starts form 2m/s and accelerates at 5m/s/s for 10 seconds
[from the question we want to find v we know u = 2 , a = 5 and t = 10]

v = 2+5 x 10

v= 52m/s

Part 2 what force is require to accelerate the giraffe to this velocity?

f= m x a

f= 500 x 5

f= 2500N
What is the kinetic energy of the giraffe

KE=1/2 x m x v x v

KE= ½ x 500 x 52 x 52

KE= 676000J or 676KJ
_

7030task

Concept
SCIENCE INQUIRY SKILLS
Text and worksheets
Extension and Interactivities
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1.
8 Forces, energy and motion
What do you remember about force, energy and motion?
page304
8.1 Ready, set, go
The speed equation, standard units and conversion, position or displacement and velocity.
page 306
Complete table on Page 305 and Questions 2 to 6
Complete questions 1, 2, 3ESO, 5 to 8 page 307
Interactive: Describing Movement
http://www.media.pearson.com.au/schools/cw/au_sch_rickard_sd4_1/dnd/sci4_5_1.html

Interactive: Understanding graphs
http://www.media.pearson.com.au/schools/cw/au_sch_rickard_sd4_1/int/GraphMovement.html
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Readiness Test
Chapter 8
Progress Test 8.1
Homework
2.a
8.2 Measuring speed
Describing instantaneous and average speed and velocity.
page 308
Optional :INQUIRY: INVESTIGATION 8.1
Ticker timer tapes
Key inquiry skills:
  • planning and conducting
  • processing and analysing data and information
Complete questions 1 to 4 page 310

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8.1 Speed and velocity
Extension: question 5

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8.2 Ticker tapes
Interactive: Describing Movement
http://www.media.pearson.com.au/schools/cw/au_sch_rickard_sd4_1/dnd/sci4_5_1.html


Look at these graphs

http://www.pinterest.com/mrwallis/distance-time-graph/
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Progress Test 8.2
Homework
2.b
8.3 Speeding up
Describing acceleration (and deceleration)
page 311
Optional: INQUIRY: INVESTIGATION 8.2
Drag strips
Key inquiry skills:
  • planning and conducting
  • processing and analysing data and information
Complete questions 1,2,3
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8.3 Acceleration
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Progress Test 8.3
Homework
3.
8.4 Let’s go for a ride
Using Newton’s First Law and inertia to describe motion.

Using EXCEL to tabulate data and plot graphs
page 313
Term 3 starter lesson
review of some ideas

rollercoasters - what are they all about
1. amovie ----
http://themeparks.lovetoknow.com/Videos_of_Roller_Coasters

2. some info ----
http://themeparks.lovetoknow.com/Physics_of_Roller_Coasters

3. make your own ---
http://pbskids.org/fetch/games/coaster/game.html

or

http://phet.colorado.edu/en/simulation/energy-skate-park

or

http://rollercoastergamesonline.com/roller-coaster-games/digital-labs-coaster-creator

4. draw some graphs of how
velocity changes
acceleration changes
Gpe and KE cahnges

INQUIRY: INVESTIGATION 8.3
Forces on cars
Key inquiry skill:
  • questioning and predicting

7030Task
complete this task -
eLesson
Science demonstrations
Watch a video from the ABC’s Catalyst program about Newton’s First Law of Motion and dry ice on a balloon. eles-1076
Complete questions 1to 5 page 315
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8.4 Inertia and motion
8.5 Force and gravity including using EXCEL


Access Code 4C4M
Access Links
Test Link http://www.classroomclipboard.com/490625/Test/56DFC7419CC24E07873D91BF61142DFB
Extension: questions 6 to 10
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Progress Test 8.4
Homework
4.
8.5 Newton’s Second Law of Motion
Using Newton’s Second Law to describe net force on an object parallel to motion.
page 316
INQUIRY: INVESTIGATION 8.4
Force, mass and acceleration
Key inquiry skills:
  • planning and conducting
  • processing and analysing data and information
  • evaluating
Complete questions 1 to 5 page 317
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8.6 Newton’s Second Law

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Progress Test 8.5
Homework
5.
8.6 What’s your reaction?
Using Newton’s Third Law to identify action reaction pairs
page 318
INQUIRY: INVESTIGATION 8.5
Just a lot of hot air
Key inquiry skills:
  • questioning and predicting
  • processing and analysing data and information

INQUIRY: INVESTIGATION 8.6
Balloon rocket
Key inquiry skills:
  • processing and analysing data and information
    • evaluating
eLesson
Newton’s Laws
Learn about Newton’s laws of motion and see them being applied in everyday life eles-0036

Complete both elessons and the web intereactive

Complete questions 1 to 6 page 319
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8.7 Newton’s Third Law
http://www.pinterest.com/mrwallis/distance-time-graph/
Interactivity
Test your ability to identify Newton’s laws in action by completing the Time Out: ‘Newton’s Laws’ interactivity. int-0055
Weblink
Use the Newton’s Laws weblink in your eBookPLUS to watch interactive animations describing Newton’s Laws of Motion. Then test yourself by taking the quiz.
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Progress Test 8.6
Homework
6.
8.7 Getting down to work
Work done on an object by a force is equal to the change in energy of the object.
page 320

Complete questions 1to 7
Weblink
Use the Rollercoaster weblink in your eBookPLUS and your knowledge about forces and motion to build a rollercoaster that is both safe and fun.

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Progress Test 8.7
Homework
7.
8.8 Systems: Energy ups and downs
Energy changes in systems
page 322
INQUIRY: INVESTIGATION 8.7
Follow the bouncing ball
Key inquiry skill:
  • processing and analysing data and information

Optional:INQUIRY: INVESTIGATION 8.8
Swing high, swing low
Key inquiry skills:
  • questioning and predicting
  • communicating
Complete questions 1 to 3 page 324

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Progress Test 8.8
Homework
8.
8.9 Making cars safe
page 325
Science as a human endeavour
http://www.youtube.com/watch?v=yUpiV2I_IRI


Complete questions 1to 7

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Progress Test 8.9
Homework

8.10 Cycle maps and storyboards
page 327

Looking back
page 330

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8.8 Forces, energy and
motion: Summary

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Achievement test
Chapter 8
NOTES 2013

Forces acting on us
Person
........Forces acting on the person
Parachutist
Gravity, air resistance, wind
Bungee jumper
gravityElastic force
Skier
gravity frictionforce exerted by the earth
Cyclist
gravity, friction, pushing the pedals
Reader

InLine Skater
friction, pushing their feet, air resistance,
Swimmer
bouyancy of the water, gravity, themselves pulling through the water
Non contact forces include - electrostatic forces, magnetic forces, gravity



Average speed can be measured in many units eg km/hr or m/s or cm/minute
In science we usually convert to metres per second




Do the online section of the test. click on the link
http://www.classroomclipboard.com/490625/Home/Test/34f5c4e538c7027703b0f361c77c62d8#/InitializeTest.xaml
Type your class as part of your last name eg ebony 10DDunkley
the test access code is X86S5
the written section will be done in class

Download this page and keep it in your note book.
Forces and Motion – key concepts Name: _
Key Concept
Vocabulary


  1. Relationships between force, mass and movement.
  2. Energy changes are responsible for changes observed in motion and shape.
Distance and Displacement
Speed and Velocity
Acceleration and deceleration
Scalar and Vector quantities
Average and instantaneous
Standard International Units
Force
Friction
Air resistance
Lift thrust
Weight
Electrostatic
Magnetic
Inertia
Mass
Equilibrium/balance
Action/reaction
Gravity
Weightlessness
Terminal velocity
Kinetic Energy
Potential (stored) energy:
Gravitational & Elastic







Priority
Suggested Activities
Extension & Variation
6.1 page 217 -9
Formulae for speed/velocity
Conversion of units
Average and instantaneous
Understanding data from graphs
Read 6.1 and answer Questions: 1-4 and 8-15 page 221

Activity: They’ve got the runs page 225
Prac: Chain reaction and Driving reaction times
The Reflex tester
Homework 6.1
Interactive: Describing Movement
http://www.media.pearson.com.au/schools/cw/au_sch_rickard_sd4_1/dnd/sci4_5_1.html

Interactive: Understanding graphs
http://www.media.pearson.com.au/schools/cw/au_sch_rickard_sd4_1/int/GraphMovement.html
6.2 page 229-230 Acceleration – speeding up or slowing down
Rate of change (of speed/velocity)
Speeding up/slowing down due to gravity
Read 6.2 Questions: 1 – 6 page 230

Activity: an accelerometer page 232
Questions 7 – 8 and 11 – 12 page 231

Extension - watch how they measure speed and acceleration on these graphs

http://physics.info/motion-graphs/
6.3 page 234 - 236 Forces
Experiencing Forces
Newton’s Law of inertia
Read 6.3 and answer Questions: 1 – 8 page 236
Prac: Experiencing Forces Booklet:
1.Types of Forces pages 3 - 4
2. Newton’s Ping Pong Balls pages 6-7
3. Circular Motion Page 8

Prac: Crash test dummies page 238 and Inertial eggs page 239
Homework 6.3

Using Data sensors to measure motion a prac:

Questions 9 – 19 page 237

Assignment: Homework 6.5 as a research
crash test dummies

http://archive.org/details/crashdummies1
http://www.youtube.com/watch?v=d7iYZPp2zYY
can you measure the velocity of various parts of the body?

http://www.youtube.com/watch?v=OoJqCsHAak8&feature=related
6.4 page 240 -241Newton’s 2nd Law, the relationship between force and mass.
Net Force
Drawing forces on the page – vectors
Questions: 1- 6 page 241
Prac: page 244


Newtons laws videos

Roller coasters exercise

http://www.nbclearn.com/portal/site/learn/science-of-the-summer-olympics

Video 1 Strength and flexibility of Oscar Pistorius
Q. Describe how the prosthetic legs help him run. What forces are involved?

Video 2 Biomechanics of Usain Bolt
Q. In order to achieve top acceleration and maintain speed Bolt needs to use more force to move more mass ( he is very tall for a sprinter) how does he do this?

Video 3 The impact of Jenny simpson
Q. How does antigravity treadmill work? How is it related to the formula F = ma

Video 4 Maximising the long jump of Brian Clay
Q. How does gravity affect Bryan's velocity? How does his take off angle help achieve a long jump.

Video 5 Sarah Robies and the mechanics of weightlifting
Q. How does sarah achieve such explosive power in weightlifting.

Now go to
http://www.nbclearn.com/portal/site/learn/science-of-the-olympic-winter-games

Choose 3 videos that could be used to explain Newtons 3 laws.
List the videos and write in bullet points why and how the video could be used to explain the each law.
Questions 7-10page 241
6.5 page 245-246 Newton’s 3rd Law
Action/reaction forces
Prac: Balloon Rockets 1 and 2 page 248
Questions: 1-5 page 246
Video: Collisions
Questions 6-11 page 247
interactive : Newton’s Laws
http://www.media.pearson.com.au/schools/cw/au_sch_rickard_sd4_1/dnd/sf4_0502.html

Interactive: Resultant Force
http://www.media.pearson.com.au/schools/cw/au_sch_rickard_sd4_1/int/forces.html

Collision Game: http://www.students.uni-mainz.de/rathb000/Pinball/Game.html
6.6 page 249-251 Gravity
Weight
Air resistance
Weightlessness
Questions: 1-12 page 251
Prac: Observing weightlessness page 255

Homework 6.6
Question 13 -18 page 251
Moon Video click on “motion due to Gravity” link of http://www.vicphysics.org/index.php?id=263
6.7page 256-258 energy, Work, Kinetic energy
Potential or stored energies:
Gravitational potential energy
Elastic potential energy
Questions: 1-7page 258
Prac: Extension of an elastic band and Efficiency of a roller coaster(hint: tape tubing to the cupboard/wall) page 260-261

Revision
Chapter Review page 262
Homework 6.9
Interactive crossword: http://wps.pearsoned.com.au/sd4/50/12994/3326638.cw/index.html

Test plus 1 A4 sheet of summary notes

Motion: Investigating Distance, Displacement, Speed and Velocity

Your task, in a group of 3 or 4, is to map out a course around the school. Individuals in your group will be timed whilst travelling this course. From this activity, you will be required to work out values of distance, displacement, speed and velocity.

Materials (per group):

- Trundle wheel
- Stopwatch
- Pen
- School map (see over the page)



Method:
  1. Using the trundle wheel, measure a course around the school and record it on your map. Use the guidelines below:

-



Your course must be between 100 and 200 metres

- You must stay within school grounds

- Your course cannot include going into classrooms

- In order to be able to calculate displacement you must be able to measure, in a straight line, from the starting position to the final position of your course, as shown on the right. If this line is through a building or other object, you will not be able to measure displacement.

  1. Record the distance of your course in the table below. Remember to include the units.

  1. Measure from the end point of your course to the starting point of your course in a straight line in order to find the displacement. Record this in the table below.

  1. Choose one person from the group to travel your course. They must do so 2 times, each using a different form of locomotion. Choose 2 of the following examples: walking, jogging, skipping, lunges, hopping. Each time the person travels the course, you should record their time with the stopwatch and write it in the table below.

  1. Return to your classroom and complete the questions below.

Results:

Mode of Locomotion
Distance of Course
Displacement of Individual
Time Taken
Average Speed
Average Velocity













Discussion:
  1. Describe the distance between distance and displacement.
  2. Calculate the average speed for each mode of locomotion using the formula distance travelled/time taken.
  3. Calculate the average velocity for each mode of locomotion using the formula displacement/time.
  4. Describe the difference between instantaneous speed and average speed.
  5. Describe the difference between speed and velocity.








Map of the school
C:Program FilesMicrosoft OfficeMEDIACAGCAT10j0304933.wmf
C:Program FilesMicrosoft OfficeMEDIACAGCAT10j0304933.wmf



Weight and potential energy and formula
One earth we have a weight force which can be calculated by

W=mass x acceleration due to gravity

W= mg acceleration due to gravity = 9.8m/s²

e.g. W= 70 x 9.8

W= 686 newtons = 686N
If we were on the moon acceleration due to gravity is 1.6/s/s therefor our weight force would be

W=70 x 1.6

W= 112 Newton’s or 112N
Energy and force
energy is neither created nor destroyed but it is transformed/

e.g. solar energy is transformed into electrical energy is transformed into moving energy
(a toy solar powered car or fan)

moving energy is called kinetic energy

kinetic energy = 1/2mv²
Find the KE of a car mass 1000kg moving at 10m/s
KE=1/2 x 1000 x 10
KE= 50000 joules or 50KJ

Gravitational potential energy (GPE)
GPE= mass x acceleration due to gravity x height (m)
E.g. find the GPE of a car of mass 1000 suspended 10m above the ground (g=9.8m/s/s)
GPE = 1000 x 9.8 x 10

GPE= 98000 joules or 98KJ

Key points
Newtons laws
first law - object stays at rest until acted on by a force
second law when a force acts on an object it will accelerate at a rate in proportion to the size of the force and the size of the mass it acts on F = ma
third law - For every force there is an equal and opposite reaction collisions forces exert equal and opposite. examples are collisions and inertia

Graphs Dist vs time graph ie dist / time
Distance / time = speed
a special case is a displacement time graph i.e. velocity = displacement / time
Big deal is displacment is distance with direction. This means displacement could be smaller than distance over the same journey eg if you went to the shops and got half way before you realised you forgot your purse and went back home and then went to the shops again. Displacement only looks at how far are you from your start ( home) While distance takes into account the return trip and back to the sshop
Velocity is speed in a given direction = this means overall velocity has to take into account the velocity back toward the starting point
speed vs time = tells us the acceleration

calculations ;
Hint how to do a physics problem
1 read the question and underline the data
2. draw a picture of what is happening
3. list the data required and the formula you might use
4. plug the data into the formula

acceleration = (final velocity – initial velocity) /times

a= (v-u)/t or v= u + at

example; find the final velocity of a giraffe with a mass of 500kg that starts form 2m/s and accelerates at 5m/s/s for 10 seconds
[from the question we want to find v we know u = 2 , a = 5 and t = 10]

v = 2+5 x 10

v= 52m/s

Part 2 what force is require to accelerate the giraffe to this velocity?

f= m x a

f= 500 x 5

f= 2500N
What is the kinetic energy of the giraffe

KE=1/2 x m x v x v

KE= ½ x 500 x 52 x 52

KE= 676000J or 676KJ