Core Practical: Investigating Thermal Energy

Aim of practical

Investigate how different materials affect thermal energy transfer

Equipment

Beakers, thermometers, kettle, insulating materials, stopwatch

Independent variable

Type of insulation or material

Dependent variable

Temperature change over time

Control variables

Volume of water, starting temperature, beaker size

Step 1

Boil water and pour equal amounts into each beaker

Step 2

Wrap beakers in different insulating materials

Step 3

Insert thermometers and start stopwatch

Step 4

Record temperature every minute for a set time

Step 5

Compare cooling curves for each material

Cooling curve meaning

Graph showing temperature drop over time

Good insulator

Slows heat loss → temperature decreases slowly

Poor insulator

Loses heat quickly → temperature drops fast

Heat loss by conduction

Through beaker walls

Heat loss by convection

From water surface to air

Heat loss by radiation

Infrared emitted from beaker surface

Reducing conduction

Use insulating materials with trapped air

Reducing convection

Use a lid to stop warm air escaping

Reducing radiation

Use shiny surfaces to reflect IR

Accuracy improvement

Use lids, start timing immediately, use digital thermometers

Key idea

Insulation reduces heat transfer by conduction, convection and radiation