Revise GCSE Physics

Question: What determines the size of increase of temperature of an object due to heating?

If we experiment with different materials, we can easily find several factors that affect the rise in temperature.

These are:

1) Transferring a greater amount of Heat energy causes a greater change in temperature.

2) For a particular material, the temperature rise is smaller if the mass is bigger; in fact doubling the mass halves the temperature increase; for the same amount of heat.

3) Equal masses of different materials have different temperature rises from a given amount of heat.

Scientists have worked out the relationship between these factors.

For every material it is possible to find a value for the energy needed to increase the temperature of 1kg of the material by 1oC.

This number is different for all materials and is called the specific heat capacity of that material.

The specific heat capacity of a substance is a measure of how much heat energy it can hold.

Definition to learn:

The Specific Heat Capacity is the energy needed to increase the temperature of 1 kg of the substance by 1oC.

Examples of Specific Heat Capacity values of some common substances

Substance Specific Heat Capacity J/kg/oC
Water 4200
Lead 128
Olive oil 1970

Notice that water has a particularly high specific heat capacity. This makes water useful for storing heat energy, and for transporting it around the home using central heating pipes. Fresh water can hold more energy than salt water, so for cooling applications fresh water is preferred even in sea water is available, i.e. in a power station, by the sea.

The word 'specific' means 'per unit of mass' in Physics.

NB. Water, ice and steam all have different Specific Heat Capacities!