Chapter 1 & 2– Heat, temperature & internal energy – Book Check

Name: ___________________

Lesson

Reading & Cornell Notes

Learning Intention

Prac/demos/activities

Questions

1

Tues

6/3

p.2-6

To be able to convert from Celsius to Kelvin

To recognise the difference between heat and temperature

To be able to explain heat using the kinetic theory

Use temperature guns to measure the temperature of a range of objects

Prac: Mixing water

1.1 Q 1-7

2

Fri

9/3

p. 7-8

To recall the Zeroth and First Law of Thermodynamics

Prac: Thermal Equilibrium

1.1 Q 8-10

3

Tues

13/3

p.10-12

To describe specific heat and to use the relationship Q = mcΔT.

Prac: Cooling Parrafin wax

1.2 Q 1-10

4

16/3

p 13-16

To describe latent heat and to use the relationship Q = mL.

To use the kinetic particle model to explain evaporation and cooling

Prac Martins Pracs\latent heat of fusion of ice.docx

1.3 Q 1-9

5

19/3

Catch up and revision for quiz

6

Tues 20/3

18-20,

25-27

To recognise and explain the three processes of energy transfer- conduction, convection & radiation

Prac:Heat Transfer – conduction and radiation

https://iview.abc.net.au/programs/todd-sampsons-life-on-the-line#pageloaded

1.4 Q 1-8

1.6 Q1-7

7

Fri 23/3

22-24,

To recognise and explain the processes of energy transfer by convection.

Prac:Heat Transfer - convection

1.5 Q 1-6

8

Mon

26/3

30-35

Quiz

To be able to describe why hot objects radiate Electromagnetic radiation

To apply Wien’s relationship

Prac: Colour of temperature

2.1 Q 1-4

10

Tues

27/3

36 - 39

To apply the relationship of P α T4 as a ratio and calculate power loss using the Stefan- Boltzmann equation.

Prac Stefan Boltzmann Law

2.1 Q 5-9

Climate Change Assignment

11

Understand the basic principals in building a climate model. You will also be able to understand how physicists and climate scientists validate their model

TED talk

https://www.ted.com/talks/gavin_schmidt_the_emergent_patterns_of_climate_change#t-710193

Excel Activity:Simple model for a climate

12

Revision

Area of Study 1 pg 83 Q 1, 3, 5, 8, 15-20 25, 26, 29, 30, 38, 44

https://learn.stleonards.vic.edu.au/vcephy/worked-solutions-yr-11-physics-textbook/

STLlink/VCEPhysics/3.6.2 Worked Solutions Yr 11 Physics textbook/Unit 1AOS1

Comment:/10

Lesson 1

Outcome

By the end of be able to convert temperatures stated in C into Kelvin, state the difference between Heat and Temperature and be able to explain heat using kinetic theory.

Temperature Gun

Use a temperature gun to measure the temperature of a number of different objects and surfaces inside and outside the room. What factors will affect your reading? What is the temperature gun actually detecting?

Mixing water

To predict and then measure the effects of mixing hot and cold water.

Equipment

Cups

Measuring cylinder

beakers

Hot water

cool water

You will run three tests of mixing the same volumes of water. Each test should use water at different temperatures.  

Set up the table below:

Temp of cup A

Temp of Cup B

Predicted temp of mix

Tempt of mix

 

 

 

 

 

 

 

 

 

 

 

 

Questions

1. What is happening? Can you give a rule to predict the temperature.

2. We controlled the volumes, why?

3. What other factors could effect this test?

Lesson 2

OUTCOME

By the end of this lesson you will be able to recall the Zeroth and First Law of thermodynamics and apply it to relevant situations.

Thermal equilibrium

1, Place a small beaker (or conical flask with rubber stopper) of hot water immersed in a beaker of cold water

2. Determine the mass of the water in each beaker (using electronic scales)

mass hot water ____________ mass cold water _________________

3. Open Pasco Capstone on the laptops choose graph plus table

4. Connect two Pasco temperature probes to track the temperature of both beakers over a 20 minute time period

Choose time for the x-axis and choose Probe A and Probe B for y-axis (using add similar measurement).

Press record when ready to start taking measurements.

4. Also note the ambient room temperature

Before the experiment:

What do you expect to happen to the temperature of both beakers (estimate any 'final' temperatures of the two )

After the experiment

Questions

1. Compare your expected final temperatures with actual final temperatures. Try to account for your results

2. Assuming that the beakers were a closed system, calculate the expected final temperature

3. In this experiment, the mass of the hot water was significantly less than the cold.

Do you think this had a bearing on the final outcome? Explain

4. If the experiment was left to run long enough, what do you think the final temperatures would be?

Use you data to make this prediction.

Lesson 3

OUTCOME

By the end of this lesson you will be able to describe specific and latent heat. You will be able to explain and apply the relationship Q = mcΔT

Cooling Paraffin wax

This investigation aims to show that the internal energy of a substance can change without a subsequent change

in temperature.

It also aims to produce a cooling curve that illustrates the concept of latent heat.

You will need the following equipment:

· large test tube containing about 2–3 cm depth of paraffin wax

· Water bath on hot plate

· Pasco temperature probe connected to Pasco Capstone, choose graph and table

Place some solid paraffin wax into a large test tube. Heat the test tube in a water bath until the temperature of the

paraffin wax is about 80 °C.

Remove the test tube from the water bath and start recording the temperature of the paraffin as it falls until the

temperature has fallen to about 30 °C. Gently and carefully stir with the thermometer while the liquid paraffin

is cooling.

1. Take a photo of the graph on the screen

2. What causes the decrease in temperature of the liquid paraffin?

3. How does the rate of cooling change as the liquid paraffin solidifies?

4. During the process of solidification, what form of internal energy is being lost from the paraffin?

Where is it going?

5. What is the meaning of the term ‘latent heat of fusion’ and how does it relate to this investigation?

Lesson 4

OUTCOME

By the end of this lesson you will be able to describe latent heat. You will be able to explain and apply the relationship Q = mL and use the particle model to explain evaporation and cooling.

Latent heat of fusion or melting of Ice:

The latent heat of ice refers to the number of joules of energy needed to melt 1 kg of ice. This is also the amount of heat that needs to be removed from 1 kg of water when making ice. The temperature of the H2O does not change as it melts or freezes, that is why it is called latent heat – a thermometer does not indicate its presence.

Instructions

· Add a quantity of warm/hot water to a beaker.

· Determine the mass of the water. Take the temperature of the water.

· Measure the temperature of the ice

· Add ice to the water and find final temperature.

· Find the mass of the mix resulting in order to find the mass of ice added.

Results

Mass of water (kg)

Initial temperature of ice

Initial temperature of the water

Final temperature of water

Final Mass (kg)

Mass of ice (kg)

1. Calculate the amount of heat needed to cool the original water (using Q1 = mcT)

c = 4200Jkg-1 K-1

2. Calculate the amount of heat needed to warm the melted ice (using Q2 = mcT)

3. Calculate the difference between these values. (Qdiff = Q1 – Q2) This value is the amount of energy taken from the water in order to melt the ice. If the ice was at approximately 0oC Qdiff can be used to determine the latent heat of fusion of ice.*

*Note: if your ice started at a temperature significantly below 0oC you should first calculate the amount of energy needed to raise the solid ice up to 0oC by using

cice = 2100Jkg-1 K-1 . This amount of energy should be added to your Q2 value

4. Calculate the latent heat of ice (using Qdiff = mLf)

5. Compare you answer to, and explain any differences between your answer and, the accepted value.

Lesson 6

OUTCOME

To recognise and explain the two processes of energy transfer- conduction & radiation

Heat transfer

1. Conduction

Place the 4 metal conducting cross on a tripod (no Gauze mat) and place a Bunsen Burner at the centre of the

cross.

Note that each of the 4 metal strips is made from a different metal.

Identify each of the metals and look up their Thermal Conductivity Coefficient.

Place a bead of solid Paraffin Wax in the indented cavity at the end of each of the 4 metal strips and turn it

upside down.

Make sure you have some sheets of paper underneath the set-up to catch the wax

Ready to light the Bunsen Burner……….. BUT NOT YET!

Use the Thermal Conductivity Coefficients that you have looked up to predict what will happen once the

bunsen burner is lit and left heating the metals for 5 minutes.

Light the bunsen burner and start the stopwatch simultaneously

Record your Observations and note how long each bud of wax takes to fall in the table below

Metal

Conductivity (W/m/K)

Predicted time

Measured time

Questions

1. How did your predictions fair?

2. How does the heat energy move through the metal?

3. Why do some metals transfer heat differently to others?

2. Radiation

You will use two cans – one black, one silver in colour. You will use a temperature probe through the hole in

each can, plugged with a cotton wool ball, to measure the temperature.

Predict what might happen when you record the temperature from each painted side. Will there be a change?

If so what will be the difference?

Add warm water to either can then using the gun thermometers, measure the temperature of the outer surface

of each colour and note the temperature of the water in each can.

1 min

5 mins

10 mins

Temperature of the water in black can

Temperature of the water in the silver can

Temperature of the black can

Temperature of the silver can

Question

1. Which colour radiated heat more?

2. Which can cooled the water quicker?

3. Explain your results.

4. How does this relate to black body radiation?

Lesson 7

OUTCOME

To recognise and explain the third process of energy transfer- convection.

3. Convection

WARNING: Potassium permanganate crystals are hazardous, always handle them with the tweezers.

Place potassium permanganate solution into a glass waste container to be disposed of later by lab technician.

Carefully place the potassium permanganate crystal in the bottom of the beaker of cold water. (3 grains)

Carefully place the cold water on the hot plate and turn it on. CAUTION: Take care working around the hot plate.

Take some before shots.

Observe and take some photos

Annotate the shots you have taken to explain what is going on.

1. Use your understanding of convection to explain what you saw.

2. How does this relate to the convection currents in the Earth’s mantle (you may need to use the internet,

use a diagram to explain)?

http://research.bpcrc.osu.edu/education/rr/plate_tectonics/mantle_convection_cell.gif

4. Convection

Perform the TEABAG Rocket (you teacher will demonstrate)

Record your Observations

https://www.questacon.edu.au/outreach/programs/science-circus/videos/teabag-rocket

https://www.google.com.au/search?q=image+for+convection+current+in+balloons&rlz=1C1SQJL_enAU779AU780&tbm=isch&source=iu&ictx=1&fir=Ro5-7eidb8C-PM%253A%252CgNXLG3cMmq2nbM%252C_&usg=__Ufs7Ih_jxWxBbsfGMAGhUYlSApw%3D&sa=X&ved=0ahUKEwiz2vGg0P_ZAhVU_GMKHawlAfIQ9QEIOTAI#imgrc=B7sKFV4n8j6gtM:

1. How does this demonstrate Convection of Heat

2. How is this related to how a hot air balloon works?

Lesson 9

OUTCOME

To be able to describe why hot objects radiate Electromagnetic radiation. Apply Wien’s formula to calculate peak wavelength and temperature.

The colour of temperature

Incandescence is the emission of light by a solid that has been heated until it glows or radiates light.

When an iron bar is heated to a very high temperature, it initially glows red, and then as its temperature

rises it glows white. Incandescence is heat made visible – the process of turning heat energy into light energy.

In this activity you will examine the light from a filament.

You will observe and measure the colour of the filament at a range of voltages against the brightness.

Equipment:

Metal colour chart

Lux meter (on device)

Colour and heat from an incandescent source are related. Watch this video

We can use this colour chart to determine the temperature of the hot filament in an incandescent light globe.

In this activity you will observe the filament from the light box on different setting from 2V to 12V.

You need to identify the colour and thus the temperature as well as measure the brightness in lux from a

distance of 10 cm from the globe.

To save your eyes, it is easier to take a photo of the filament or project the light onto a white screen and

observe the colour reflected.

Fill in the table below

Voltage

Colour description

Corresponding temperature (oK)

Calculated peak wavelength (nm)

Brightness (lux)

2

4

6

8

10

12

Create a plot of Temperature vs Brightness

Comment on the shapes and how they compare

Comment on how calculated peak wavelength corresponds to the observed colours.

http://www.scienceinschool.org/sites/default/files/teaserPdf/black_body.pdf

Lesson 10

OUTCOME

To apply the relationship of P α T4 as a ratio and calculate power loss using the Stefan- Boltzmann equation.

The Stefan- Boltzmann Law

Instructions:

Put hot (boiling) water into a black can and a silvered can. Place a temperature probe in each can and measure the temperature drop over a period of 20-30 minutes.

Measure the mass of the water in each can.

Measure the ambient room temperature.

Surface area of can = (2πrh +2πr2)

= (2x 3.14 x 0.03 x 0.12 +2x 3.14x 0.032)

= 0.0283m2

Results:

Time taken for change in temperature: __________ mins ____________ secs

Starting temp (oC)

Starting temp (K)

Final temp (oC)

Final temp (K)

Mass of water(kg)

Room temp (oC)

Room temp Ts (K)

Black can

Silver can

Calculations:

Actual power loss (black can):

Calculate the energy lost from the water during the experiment using ∆Q = m c ∆T

Convert this into Power loss. (Actual power loss.)

Power (W) = rate that energy is gained or lost = Energy/time

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Expected power loss (black can) – radiation:

Calculate the Power loss from the black can using the formula P = e A σ (T4 - Ts4) (Expected power loss)

Take e as 0.92 for the black can.

σ = 5.67 × 10-8 W m-2 K-4

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Determine the difference between expected and actual power loss. This difference can be assumed to be power loss due to other means of heat transfer.

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Extension:

Using these ideas, get an estimate of the emissivity for the silvered surface. (Consider- would the power loss due to conduction and convection be the same for the black and silver cans?, Why? Why not?). Compare your calculated value with those on pg 36 of the textbook.

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Discussion questions

1. Describe possible ways which heat might be lost from the can.

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2. Describe ways in which you did (or could) reduce heat loss apart from radiation.

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3. Discuss sources of error for this experiment.

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4. Comment on the final values which you calculated.

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Lesson 11

OUTCOME

By the end of the lesson you will be able to understand the basic principals in building a climate model. You will also be able to understand how physicists and climate scientists validate their model

Simple model for a climate

Activity: Investigating Arctic Sea Ice

The data in Energy budget figure below can be used to set up a spreadsheet to investigate the effect of changing one of the parameters, in this case the amount of Arctic Sea Ice and the amount of energy 'reflected by surface'.

https://www.youtube.com/watch?v=5w8L1utaVo4&feature=youtu.be

The spreadsheet below has been set up with these data values. They are in column B.

Excel Activity: Climate modeling activity.xls

A simplified climate model has been constructed in the remaining columns. How was it constructed and how can it be interpreted?

Physics behind the model

If the amount of energy reflected by sea and land ice decreases from 30 to 25 Wm–2, then 5 Wm–2 of energy has been absorbed by sea water. This increases the total amount of energy absorbed by the earth's surface, which is greater than the amount of energy emitted, and so the surface temperature increases. This leads to more energy being emitted. These changes are in column D.

But before the changes can be calculated, the model needs to make an assumption. How is the extra energy being emitted spread across the different forms of thermal, evapo-transpiration and surface radiation? This model assumes that the proportions stay unchanged. These values have been calculated in column C.

The extra energy emitted by the surface is mostly absorbed by the atmosphere, with a small amount going straight out into space. The atmosphere then emits this extra energy; some out into space, but some back down to the surface. Once again, the proportions are kept the same. These values have been calculated in column E.

The consequence of the changes in column D is to shift the whole earth away from energy equilibrium as you can see from the Energy balance values in column D compared with the starting values in column B. The changes in column E make some amends, but by the atmosphere emitting a small amount of energy back to the surface, the whole process repeats itself but with smaller values. With repeated iterations, the values in the energy balance get closer to agreement, when the surface will stabilise at a higher temperature and a higher energy output.

Questions

1. If the energy 'reflected by surface' changed from 30 Wm–2 to 25 Wm–2, how much more energy would the surface be emitting after the new equilibrium is reached?

2. The energy out for the whole earth, after the new equilibrium, is reached back to the value it started at. Why is this the case?

3. Use the Stefan-Boltzmann relationship to determine the increase in surface temperature in Kelvin and degrees.

A second spreadsheet looks at the effect of increased concentration of carbon dioxide in the atmosphere. In this investigation, the energy reflected by the surface is reset to 30, but the proportion of the radiation from the surface that escapes to outer space has been reduced to 5% from 8.1%

4. How much more energy would the surface be emitting after the new equilibrium is reached?

Watch this TED Talk video on Climate Models

What makes a model useful? How do we know if a model is accurate?

TED talk

https://www.ted.com/talks/gavin_schmidt_the_emergent_patterns_of_climate_change#t-710193