Work, Energy and Machines
What is work done?
Do Now
Work is done whenever a force moves something over a distance.
When a force moves an object, or deforms it, energy is transferred between stores.
Work, Energy and Machines
Work
Starter
Task 1: Pick your bag up from the ground
Task 2: Slide your book across your desk
Task 3: Lift up your arm above your head
Challenge: How do you calculate work done?
Work, Energy and Machines
Calculate the work done
Task 1:
Work, Energy and Machines
What is a lever?
HINT: The longer the lever, and the further the effort acts from the pivot, the greater the force on the load will be.
Work, Energy and Machines
What is a lever?
Challenge: Draw a short lever, long lever and a lever that in far away from the pivot.
Work, Energy and Machines
Heat Transfer - Conduction
What are the 4 principles of particle theory?
Do Now
Heat Transfer - Conduction
What Am I?
Starter
Challenge: What are my properties?
Heat Transfer - Conduction
What Am I?
Starter
Conduction is the process by which heat energy is transmitted through collisions between neighbouring particles
Heat Transfer - Conduction
What is conduction?
Do Now
Heat Transfer - Conduction
What are the 4 principles of particle theory?
Do Now
When a substance is heated, the particles start to move around (vibrate) more
Neighbouring particles collide (bump) into each other, transferring energy from particle to particle
Heat Transfer - Conduction
How does conduction occur?
P3.3.1.3 Explain conduction in solids in terms of molecular vibrations and transfer by electrons
Challenge: Why does conduction not happen in gases?
Heat Transfer - Conduction
What is conduction?
Compare and contrast conductors and insulators
Challenge: What kitchen utensils conduct heat? Why?
Heat Transfer - Conduction
Draw and annotate the particles conducting heat
P3.3.1.1 Recognise and name typical good and bad thermal conductors
Challenge: Suggest and justify a material to make your handle
Metals have a sea of electrons which transport the energy
Heat Transfer - Conduction
Conductors Vs Insulators
Task 2
Air has its no ‘free floating’ electrons
Heat Transfer - Conduction
Predict what pin will fall off and why?
P3.3.1.2 Describe experiments to demonstrate the properties of good and bad thermal conductors
Do not walk around with away from your gas cooker
Keep the heat down as low as possible
Add a small amount of oil to help with no-stick
Do not walk around with hot objects.
Heat Transfer - Conduction
Cooking the perfect egg!
P3.3.1.2 Describe experiments to demonstrate the properties of good and bad thermal conductors
· Describe what you observed happening to the frying pan as it heated up. How did the surface of the pan change?
· Explain how the particles in the metal pan responded to the application of heat. What changes did you notice in their movement and arrangement?
· Compare and contrast the processes of conduction, convection, and radiation in the context of heating the frying pan. How does each contribute to heat transfer?
· What practical implications does understanding heat transfer have for cooking? How might chefs use this knowledge to improve their culinary skills?
· If you were to design a more efficient frying pan, what factors related to heat transfer would you consider?
Heat Transfer - Conduction
Cooking the perfect egg!
P3.3.1.2 Describe experiments to demonstrate the properties of good and bad thermal conductors
Heat Transfer - Conduction
Can you talk for 45 seconds without stopping.
“Describe how a metal rod conducts heat”
P3.3.1.2 Describe experiments to demonstrate the properties of good and bad thermal conductors
Particles
Colliding
Neighbour
Vigorously
Vibrating
Moving Faster
Heated
Transfer
Energy
Passing On
Heat Transfer - Conduction
Checkpoint
4 Principles of Particle Theory
3 States of Matter
2 Words to describe how good or poorly a material transfers energy
1 Definition of conduction
Challenge: Describe an investigation to test conduction
Heat Transfer - Convection
Discuss what is happening in this animation
Do Now
Challenge: What would happen if you put a metal object at the end of the rod
Heat Transfer - Convection
What are the three states of matter?
Starter
Challenge: What state of matter does conduction happen in?
Heat Transfer - Convection
What do these have in common?
P3.3.2.1 Recognise convection as the main method of energy transfer in fluids
Challenge: How could these states of matter transfer heat energy?
Heat Transfer - Convection
Why does ice float? Why do helium balloons float?
P3.3.2.2 Relate convection in fluids to density changes
Syllabus Link: Density
Heat Transfer - Convection
What is convection?
Task 1
Heat Transfer - Convection
Circle the correct term.
P3.3.2.2 Relate convection in fluids to density changes
Challenge: Teach someone what happens to density in convection currents
u
Heat Transfer - Convection
Organise these in the correct order
P3.3.2.3 Interpret and describe experiments designed to illustrate convection in liquids and gases (fluids)
When the particles gained energy, they spread out
When the particles are far away from the heat source, the move less
Heat Transfer - Convection
Describe what you can see using the words below
P3.3.2.3 Interpret and describe experiments designed to illustrate convection in liquids and gases (fluids)
Convection Current
Heat Transfer - Convection
Complete the exam question
P3.3.2.3 Interpret and describe experiments designed to illustrate convection in liquids and gases (fluids)
Discuss the rules with density and particles.
What makes particles fall?
What makes particles rise?
Why?
Heat Transfer - Convection
Rules and Tools
Plenary
Heat Transfer - Convection
Combine your knowledge of conduction and convection to help cook pasta
Stretch
Heat Transfer - Radiation
Choose an image and describe what is happening
Do Now
Heat Transfer - Radiation
Organise these in the correct order
Starter
?
Heat Transfer - Radiation
Which one do you think radiation happens in?
Starter
Heat Transfer - Radiation
What is radiation?
P3.3.3.1 Recognise radiation as the method of energy transfer that does not require a medium to travel through
Because no particles are involved, radiation can even work through the vacuum of space
Challenge: What is a vacuum?
Heat Transfer - Radiation
What do these have in common?
Task 1
Heat Transfer - Radiation
Which order will these dry first? Why?
P3.3.3.3 Describe the effect of surface colour (black or white) and texture (dull or shiny) on the emission, absorption and reflection of radiation
Challenge: Suggest why cricket players wear white
Heat Transfer - Radiation
Complete the table below
P3.3.3.3 Describe the effect of surface colour (black or white) and texture (dull or shiny) on the emission, absorption and reflection of radiation
High/Good
| Waves | Solids | Liquids | Gases |
Conduction | | | | |
Convection | | | | |
Radiation | | | | |
Heat Transfer - Radiation
Add a yes or no for the medium of heat transfer
Checkpoint
Elkie loves learning new things.
She asked me if she could learn about Heat Transfer
Create a children’s book to explain process of conduction, convection and radiation
Make it simple, make it colourful and make it creative.
We will read the books as a class
Heat Transfer - Radiation
Decide if the following statements are true or false
Checkpoint
Challenge: Write your own true or false questions
| What? | How? |
IV | The colour of the beaker | Change the colour the beaker is wrapped in |
DV | Amount of radiation | Temperature maintained in a beaker of hot water © |
CV | Amount of water, time, starting temperature, size of beaker | Measure water and use same beaker |
R | Repeat | 5 times |
A | Average | Calculate the mean |
A | Anomaly | Eliminate any anomalous |
Heat Transfer - Radiation
Investigate Radiation
Task 3
Heat Transfer - Radiation
Diagram and Results Table
P3.3.3.4 Interpret and describe experiments to investigate the properties of good and bad emitters and good and bad absorbers of infrared radiation
Heat Transfer - Radiation
Plot your data
Task 4
Challenge: What 5 aspects must you remember?
Support: Temperature = y axis
Heat Transfer - Radiation
Complete the big question
Plenary/HW
Support: Revise over old books
Heat Transfer - Radiation
Fill in the missing word
Plenary
Heat Transfer - Radiation
Summarise Radiation in 10 words or less
Plenary
Challenge: Summarise it in 4 images of less
Insulation
Talk for 1 minute about heat transfer
Do Now
Insulation
How do you prevent heat transfer?
P3.3.4.1 Identify and explain some of the everyday applications and consequences of conduction, convection and radiation
Challenge: Why would you want to prevent heat transfer
Support: How does heat transfer?
Insulation
Mr Richardson lost his precious water bottle. Can you help him find a new one?
Plenary
Insulation
P3.3.4.1 Identify and explain some of the everyday applications and consequences of conduction, convection and radiation
Insulation
P3.3.4.1 Identify and explain some of the everyday applications and consequences of conduction, convection and radiation
Insulation
Je Hyeok wants to insulate his home. Can you help him out?
Plenary