FQ - 2B - 24 de marzo de 2022

• Natuurkunde / Scheikunde
• Middelbare school
• havo
• Leerjaar 2

FQ - 2B

• repeat last class
• conduction
• convection
• radiation
•  thermal efficiency

Exam

We finished the theory.

When?

Repetition

• Thermal expansion + equation
•  L = L₀ (1 + α x ΔT)
• Expansion in gases
• Thermal equilibrium
• How much Joules is 1 cal?

Video

Watch the video and take notes on what's important!

Conduction

The process by which heat is transferred from one point to  another in a solid.

- Thermal conductors: transfer thermal energy quickly.

- Thermal insulators: tranfer thermal energy slowly.

Good thermal conductor has a high thermal conductivity.

Sea breezes
(convection)

Air on lang becomes less dense as it

heats up and rises. Cooler air from

the sea moves in over the land.

At night it's the opposite effect.

Radiation

Radiation is the process of heat transfer by which bodies emit energy that can move through a vacuum.

Heat transfer by conduction obeys Newton's Law of Cooling

The speed at which heat is transferred by thermal conduction through the walls of a material depends on:
- the difference between the temperatures on either side of the wall

- the area of the walls

- the thermal conductivity of the material used in the walls

- the thickness of the walls

Let's practise

Make exercises 12, 13, 14, 16, 17, 19, 20, 21 & diagram on page 133

Finished with exercises? Process the theory (mindmap/summary)