6.7

Tell the person next to you…
1. If the field lines are close together, what does this tell you about the field?
2. If the field lines are widely spaced, what does this tell you about the field?
3. If the magnetic field lines are parallel to each other, what does this tell you about the field?

Answers
1. The field is strong
2. The field is weak
3. The field is of a constant strength - a "uniform" field

15:08
· 6.7 know how to use two permanent magnets to produce a uniform magnetic field pattern

[cid:image001.jpg@01CCBA6E.BBDBB9D0]

[cid:image002.png@01CCBA6E.BBDBB9D0]

· When the field lines are parallel, the field will be uniform (constant field strength)

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6.4

Plenary questions and the Earth's Magnetic field.ppt Download this file

• 6.4 understand the term ‘magnetic field line’

Observing the magnetic field around a bar magnet and a wire

magnetic field around a bar magnet and wirehttp://www.youtube.com/watch?v=pjJSa148CKI

· Use iron filings to observe the magnetic field around a bar magnet
· Use plotting compasses to observe the field
· Use the 3D field demonstrator to observe field

6.4 Field around bar magnet simulation

28 November 2011

15:06

Website:

http://www.walter-fendt.de/ph14e/mfbar.htm

Embed code for your blog:

Example:

http://maddog11physics.posterous.com/bar-magnet

6.4 plenary questions and Earth's Magnetic Field

01 December 2011

19:12

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6.4 plenary 2

01 December 2011

19:14
· Can you stop a magnetic field?
· Watch the incredible flying paperclip demo to find out!
· Now you can try with your hand...

6.6

· 6.6 sketch and recognise the magnetic field pattern for a permanent bar magnet and that between two bar magnets
[cid:image001.jpg@01CCBA6D.01A20A20]

6.5 and 6.3

Demo
· How I turned a needle into a compass to find my way out of the jungle...

6.5 and 6.3

28 November 2011

15:07
· 6.5 understand that magnetism is induced in some materials when they are placed in a magnetic field
· 6.3 recall the properties of magnetically hard and soft materials

Practical
1. Stroke a magnet along a steel bar and an iron bar
2. Try picking up some bar clips
3. Bang both bars on the desk
4. Now try picking up the paperclips again
5. Repeat the experiment but this time put the bars inside an electromagnet instead of stroking them

Explanation
· Steel is a magnetically hard material. It retains its magnetism when magnetised
· Iron is a magnetically soft material. It can be magnetised, but easily loses its magnetism

6.2

Neodymium magnets are strong…

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6.2 starter 2

01 December 2011

18:23
· Magnetic materials are attracted by magnets.
· Can you list the 5 magnetic materials?

(3 elements, 2 compounds)

Answer

3 elements
1. Fe (iron)
2. Co (cobalt)
3. Ni (nickel)

2 compounds
1. Steel (an alloy of iron)
2. Fe3O4 (magnetite (lodestone), one of the oxides of iron)

And the exceptions that prove the rule… ?
· Magnet moves water - diamagnetism

· Levitating frog...

· Ferrofluids…

(Picture on page "6.4 6.5 6.6 6")

6.2

01 December 2011

18:21
· 6.2 recall that magnets repel and attract other magnets, and attract magnetic substances

Question

You have 3 bars that all look the exactly the same but they are made from:
1. a magnet
2. steel
3. aluminium

You are given a horseshoe magnet. How can you use this to tell which bar is which?

Answer
1. The bar magnet will be attracted to one pole of the horseshoe magnet and repelled by the other
2. The steel bar will be attracted to both poles of the horseshoe magnet
3. The aluminium bar will be attracted to neither pole of the horseshoe magnet

6.2 Plenary - Multichoice questions

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Attraction and repulsion quiz.swf Download this file

6b Plenary Multichoice questions.pptx Download this file

P6 student objectives sheet

P6 IGCSE Physics Student Objectives.doc Download this file

5.19 Boyle's Law

· 5.19 use the relationship between the pressure and volume of a fixed mass of gas at constant temperature:

p1V1 = p2V2

p1 = Pressure at the beginning [kPa, bar or atm]

V1 = Volume at the beginning [m3 or cm3]

p2 = Pressure at the end [kPa, bar or atm]

V2 = Volume at the end [m3 or cm3]

(Note: can use any units for V and p as long as they are the same at the beginning and end)

5.19 Boyle's Law demos

02 November 2011

20:01

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Fun with the vacuum pump!
· Marshmellows
· Food colouring in pipettes
· Surgical gloves

5.19 Ideal graph and conclusion

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5.19 Experiment

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5.18

Cloud formation
· Place a little water in the bottom of a 1½ litre plastic bottle
· Squeeze a few times
· Introduce a small amount of smoke
· Squeeze and release several times
· When you squeeze, the cloud disappears; when you release, the cloud reforms

Explanation
· When the pressure increases the temperature increases and vica versa
· The smoke particles are nucleating sites on which the water can condense

5.18 Gay-lussac's law

11:11
· 5.18 use the relationship between the pressure and Kelvin temperature of a fixed mass of gas at constant volume:

p1 / T1 = p2 / T2

p1 = Pressure at the beginning [kPa, bar or atm ]

T1 = Absolute temperature at the beginning [K]

p2 = Pressure at the end [kPa, bar or atm]

T2 = Absolute temperature at the end [K]

(Note: the units of temperature must be Kelvin, not oC! The units of pressure can be any, as long as the same at the beginning and the end)

5.18 Ideal graph and conclusion

09 November 2011

15:15
[cid:image001.png@01CCA464.D69055D0]

5.18 Question

Collins, p.116

[cid:image002.jpg@01CCA464.D69055D0]

p1 p2
------ = ------
T1 T2

p1 = 3
T1 = 293
T2 = 328
p2 = 3.36 Bar

a. If we cool the gas in a rigid, sealed tin can, what happens to the pressure inside the can? (1 mark) It will Decrease
b. Explain your answer to part a. by using the Kinetic Theory (4 marks) As the Temperature decreases in the container and volume stays the same, the pressure will decrease as the particles will move slower so they will not hit the walls of the container as hard

See the full gallery on Posterous

5.18

________________________________________
From: Matt Baker
Sent: Wednesday, November 16, 2011 1:37 PM
To: Andrew Koomenjoe Nyaga; Arisara Amrapala; Boondaree Chang; Chrischawit Chomsoonthorn; Christopher Lo; Connor Blair Sailes; Frazer Allen Briggs; Huei-Yu Daniel Lo; Isabel Catriona McDonald; Kavin Supatravanij; Luke Michael Gebbie; Lydia Anna Foley; Morrakot Sae-Huang; Puchawin Borirackujarean; Qing Tang; Sanyam Grewal; Sebastien Grimm; Soo Hyun Lee; Tatiksha Singh; Usa Wongsanguan; Yanida Areekul; Yi-Lin Huang
Subject: 5.18

5.17 Demo

02 November 2011

19:56

Cloud formation
· Place a little water in the bottom of a 1½ litre plastic bottle
· Squeeze a few times
· Introduce a small amount of smoke
· Squeeze and release several times
· When you squeeze, the cloud disappears; when you release, the cloud reforms

Explanation
· When the pressure increases the temperature increases and vica versa
· The smoke particles are nucleating sites on which the water can condense

5.18 Gay-lussac's law

28 October 2011

11:11
· 5.18 use the relationship between the pressure and Kelvin temperature of a fixed mass of gas at constant volume:

p1 / T1 = p2 / T2

p1 = Pressure at the beginning [kPa, bar or atm ]

T1 = Absolute temperature at the beginning [K]

p2 = Pressure at the end [kPa, bar or atm]

T2 = Absolute temperature at the end [K]

(Note: the units of temperature must be Kelvin, not oC! The units of pressure can be any, as long as the same at the beginning and the end)

5.18 Ideal graph and conclusion

09 November 2011

15:15
[cid:image001.png@01CCA464.D69055D0]

5.18 Question

07 November 2011

15:08

Collins, p.116

[cid:image002.jpg@01CCA464.D69055D0]

P1 P2
------ = ------
T1 T2

P1 = 3
T1 = 293
T2 = 328
P2 = 3.36 Bar a. If we cool the gas in a rigid, sealed tin can, what happens to the pressure inside the can? (1 mark) It will Decrease b. Explain your answer to part a. by using the Kinetic Theory (4 marks) As the Temperature decreases in the container and volume stays the same, the pressure will decrease as the particles will move slower so they will not hit the walls of the container as hard

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5.17

Why do the eggs get sucked into the bottles?!

Explanation
· The burning paper in the bottle heats the air in the bottle
· When the egg gets placed on top, the oxygen supply in the bottle is rapidly depleted and the paper goes out
· The bottle is sealed by the egg and now has a constant volume of gas inside
· The hot gas in the bottle now starts to cool which reduces the pressure inside the bottle
· The pressure outside the bottle remains unchanged and so there is now an unbalanced force on the egg which accelerates the egg into the bottle

· 5.17 describe the qualitative relationship between pressure and Kelvin temperature for a gas in a sealed container

: http://phet.colorado.edu/en/simulation/gas-properties

· Put 5 pumps of gas in
· Set volume as the Constant Parameter
· Heat to 1000K
· Watch what happens to the Pressure

Conclusion
· If you increase the temperature, you increase the pressure

Video - Egg sucked into a bottle by Guy-Lussac's Law.flv Watch on Posterous

5.18 Gay-lussac's law

5.18 use the relationship between the pressure and Kelvin temperature of a fixed mass of gas at constant volume:

p1 / T1 = p2 / T2

p1 = Pressure at the beginning [kPa, bar or atm ]

T1 = Absolute temperature at the beginning [K]

p2 = Pressure at the end [kPa, bar or atm]

T2 = Absolute temperature at the end [K]

(Note: the units of temperature must be Kelvin, not oC! The units of pressure can be any, as long as the same at the beginning and the end)

5.18 Ideal graph and conclusion

See the full gallery on Posterous

Untitled

Ideal Gas - temperature vs average KE of particles blank table.xlsx Download this file

Untitled

Ideal Gas - temperature vs average KE of particles blank table-1.xlsx Download this file

Untitled

physics Questions.docx Download this file

Untitled

Click to Run

Untitled

Click to Run

5.14

5.14 describe the Kelvin scale of temperature and be able to convert between the Kelvin and Celsius scales

Converting Centigrade to Kelvin
TK = ToC + 273

Converting Kelvin to Centigrade
ToC = TK - 273

TK = Temperature in Kelvin [K]

ToC = Temperature in Degrees Centigrade [oC]

· Collins p.118

[cid:image001.jpg@01CC9EF1.5FFE25A0]

1. T absolute zero (- 273 degrees centigrade) is when kinetic energy is at zero and the particles are not moving, you cannot go past this point as the particles cannot lose anymore energy as there is non left. 2. a) 20°C = 293K, ii) 150°C = 423K, iii) 1000°C = 1273°C
b) 300K = 27°C ii)650K= 377°C iii) 1000K = 727°C

5.13

18:17
· How can you fit a giraffe, 2 dogs and a swan into a standard laboratory beaker?!

5.13 Starter 2

02 November 2011

18:17

· Use particle theory to explain why the gas in the balloon contracts

Explanation
· The temperature of the gas inside the balloon decreases so the average speed of the particles decreases
· Consequently the gas particles collide with the walls of the balloon with less force and less collisions per second
· Because the walls of the container are flexible, the volume decreases

5.13 Charles' law

28 October 2011

11:10
· 5.13 understand that there is an absolute zero of temperature which is –273oC

>

Open the Charles' law interactive experiment
· Adjust the temperature
· What’s the relationship between temperature and volume?
· Plot a graph of V against T
· Take a screen shot of the graph

5.13 results and conclusion

28 October 2011

11:10
[cid:image001.png@01CC9EF1.310E7600]
[cid:image002.png@01CC9EF1.310E7600]

Conclusion
· Volume is directly proportional to absolute (Kelvin) temperature
· V α T

Charles' law interactive experiment.swf Download this file

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5.11

>

· You're looking at smoke particles in air under a microscope
· They appear to be jiggling about
· Why?

· (Don't worry if you can't work this out straight away - Albert Einstein was the bloke who eventually explained what's happening here!)

5.11

28 October 2011

11:10
· 5.11 understand the significance of Brownian motion

>

Model 1
· What does the red puck represent?
· What do the metal balls represent?
[cid:image001.png@01CC9989.A14EFF60]

[cid:image002.png@01CC9989.A14EFF60]

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Model 3
· What do the "smoke" particles look like?
· Why are they moving?
· What do the "air" particles look like?

5.11 explained

28 October 2011

11:10

Model 1
· What does the red puck represent?
o The large, visible smoke particle
· What do the metal balls represent?
o The small, not visible air particles

Model 2
· What do the small red particles represent?
o The small, not visible air particles
· What does the large blue particle represent?
o The large, visible smoke particle
· What does the view on the left of the screen represent?
o The view through the microscope lense
· Why can‘t you see the red particles in this view?
o They are too small to see

Model 3
· What do the "smoke" particles look like?
o They are the 5 large, sand coloured particles
· Why are they moving?
o Small, fast moving air particles are colliding with the smoke particles and making them move
· What do the "air" particles look like?
o They are the numerous, small, white particles

5.11 Questions

02 November 2011

17:21
1. Draw the path of a smoke particle in air (3 marks) Away from the air ----> they are pushed in whatever the direction the air particles move 2. Explain what is meant by Brownian Motion of smoke particles in air and how it provides evidence for air particles (4 marks)
Brownian motion of smoke particles is the random movement of particles, and this provides eidenc as The smoke particle has a jerky motion.
As (invisible) air molecules collide with the smoke particle,
they push it about in different directions at random.
3. What change would you expect to see in the movement of the smoke particles if the air was cooled down? Why? (2 marks)
the movement would slow down as the air particles had less kinetic energy.

brownian_motion.swf Download this file

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5.12+5.15

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Questions
· Why does the needle on the meter move when gas particles are introduced into the box?
· What does the meter measure?

Answers
· The gas particles collide with all of the walls of the container. The wall on the right moves outwards and moves the needle.
· Pressure. The gas particles colliding with the walls makes a force on the walls. The walls have a surface area so the quantity measured is pressure, p=F/A.

5.12+5.15 Questions

02 November 2011

15:55
· 5.12 recall that molecules in a gas have a random motion and that they exert a force and hence a pressure on the walls of the container
· 5.15 understand that an increase in temperature results in an increase in the speed of gas molecules
[cid:image001.png@01CC9986.E18EA0B0]

Try the animation http://www.lon-capa.org/~mmp/kap10/cd283.htm
1. How do the particles create a pressure?
By bouncing off the walls of their container.
2. If you increase the temperature, how does the movement of the particles change?
the movement of particles gets faster
3. If you increase the temperature, how does the number of collisions per second change?
it increases
4. If you increase the temperature, what does this do to the pressure?
it increases the pressure

5.12+5.15 Plenary

02 November 2011

15:55

>

Ideal gases - summary of terms.pptx Download this file

Questions

What is the difference between evaporating and boiling?

Boiling is rapid evaporation anywhere in the bulk liquid and at a fixed temperature called the boiling point and requires continuous addition of heat.
The rate of boiling is limited by the rate of heat transfer into the liquid.
Evaporation takes place more slowly than boiling at any temperature between the melting point and boiling point, and only from the surface, and results in the liquid becoming cooler due to loss of higher kinetic energy particles.

Questions

Why do solids keep their shape and why don't liquids and gases ?

As solids have a tightly packed formation and cannot move around and there is very strong bonds between particles, where as liquids and gases don't have a regular formation and can move around, so they are able to change shape.
Why do solids and liquids have a fixed volume but gases can spread out to fill their container?

As gases have no attracting forces between the particles and no fixed shape or volume, where as solids and liquids do have stronger bonds between particles and solids have a fixed shape and both have a fixed volume.

5.7 and 5.8

Instructions for Objective 5.7 and 5.8

1. 5.7 and 5.8 Starter. Find out the names of the processes. Research on the internet if necessary. No need to blog this.

2. 5.7 and 5.8. Forward this e-mail to your blog and type the answers into the e-mail.

3. 5.7 and 5.8 Experiment. I’m afraid you can’t do the expt until we get back but watch the video clip to see how it’s set up and have a look at the graph of the results.

4. 5.7 to 5.10 Plenary 1. Play the attached “States of Matter”

5. 5.7 to 5.10 Plenary 2. Play the attached “Fill the trucks”

6. PhET States of matter simulation - embedding into your Posterous blog. Embed in your blog and then have a play

5.7 and 5.8 Starter

28 October 2011

11:00
· What are the 6 processes shown by the arrows?
[cid:image001.png@01CC9575.87F11DE0]

Solid ----> liquid = melting
Liquid ----> Gas = evaporating Gas -----> liquid = condensing Liquid ---->solid = freezing
Solid ----->Gas = reverse sublimation Gas ----> solid = sublimation

5.7 and 5.8

28 October 2011

10:20
· 5.7 understand that a substance can change state from solid to liquid by the process of melting
· 5.8 understand that a substance can change state from liquid to gas by the process of evaporation or boiling
· Questions from Collins p.112
· Answer in Bullet Points!
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[cid:image003.png@01CC9575.87F11DE0]
· Use following pages from Collins as a resource to help you
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[cid:image020.jpg@01CC9576.07199B60]
[cid:image021.jpg@01CC9576.07199B60]
[cid:image022.jpg@01CC9576.07199B60]
[cid:image023.jpg@01CC9576.07199B60]

5.7 and 5.8 Experiment - Cooling Curve of Stearic Acid using datalogger

15 October 2010

14:34

[cid:image024.jpg@01CC9576.07199B60]

5.7 to 5.10 Plenary 1

28 October 2011

12:19

· Play the Stage 1 game to test your knowledge of solids, liquids and gases
· Play the Stage 2 game to test your knowledge about changes of phase!

5.7 to 5.10 Plenary 2

28 October 2011

12:19

Play the Level 1 game to test your knowledge of the properties of solids, liquids and gases

Extension: Play the Level 2 game to extend your knowledge about changes of phase!

PhET States of matter simulation - embedding into your Posterous blog

28 October 2011

11:14
· Create a post
[cid:image016.png@01CC9575.87F11DE0]
· Turn on HTML editor
[cid:image017.png@01CC9575.87F11DE0]
· Copy in this text and Publish

Click to Run

· Success! Now have a play with the simulation...
[cid:image018.png@01CC9575.87F11DE0]

states of matter drag and drop plenary.swf Download this file

Fill the trucks - Properties of s,l,g.swf Download this file

5.9 and 5.10 starter

s,l,g animation.swf Download this file

States.docx Download this file

states 1.docx Download this file