Lesson 9

• Physics
• Middelbare school
• vwo
• Leerjaar 3

Chapter 3 Energy — Section 2 & 3

This lesson

• Some practical info
• Understanding a calorimeter
• Exercises specific heat capacity
• Double glass
• Heat transfer
• Quality of insulation

Learning goals

At the end of this lesson you can:

• Explain how a caloriemeter works and what it is used for
• Rearrange the formula for specific heat
• Explain how double glass works
• Name the three forms of heat transfer and examples for each
• Do calculations on quality of insulation

Practical info

•  The practical will take place the first week after the carnavals break.
• For this you will have to study chapter 3 section 1 to 4.


• If we have time left this period, we will also do a poster assignment.
• If we don't have enough time, we will do the poster assignment next period.

Section 2 – Heating

Understanding 

a calorimeter

• What components do you notice?
  
• What is their function? 
  
• What is the purpose of a calorie meter?
  

Understanding 

a calorimeter

A calorimeter is used to measure the amount of heat required to raise the temperature of a certain amount of water

Specific heat capacity

Q: Heat in joules (J)

c: The specific heat capacity of a s substance (J/(g•ºC)

m: The mass of a substance in grams (g)

ΔT = T end  - T start : The temperature difference (ºC)

Q=c⋅m⋅ΔT

The property of a substance of how easily it heats up.

Section 3 — Inulsation

Understanding double glass

Heat transfer

Three forms of heat transfer:

• Conduction
  
• Convection
  
• Radiation
  

Exercise — Heat transfer

Three forms of heat transfer:

• Conduction
  
• Convection
  
• Radiation
  

Come up with three examples of for each form of heat transfer

Exercise — Heat transfer

Three forms of heat transfer:

• Conduction
  
• Convection
  
• Radiation
  

Come up with three examples of for each form of heat transfer

Conduction

• A radiator
  
• Holding a hot cup of tea
  
• A pan on a stove
  

Convection

• Warm water flowing through a tap
  
• A cold breeze in the summer
  
• Steam coming of boiling water
  

Radiation

• A campfire
• The sun
• Electric heating

Quality of insulation

Q: Heat in joules (J)

U: the quality of insulation of the wall (W/m²•ºC)

A: The surface area of the wall (m²)

ΔT = T end  - T start : The temperature difference (ºC)

Q=U⋅A⋅ΔT

The property of a material of it's quality of insulation

Practice

• Work on exercise 8 and 9 in pairs of two
  
• If you're done with those — start with exercise 1, 2, 4, 5 and 6

Learning goals

At the end of this lesson you can:

• Explain how a caloriemeter works and what it is used for
• Rearrange the formula for specific heat
• Explain how double glass works
• Name the three forms of heat transfer and examples for each
• Do calculations on quality of insulation