#### What everyone needs to know:

Heat energy transfer can be measured by using the temperature change of a substance and its specific heat capacity (the measure of how much energy is needed to change its temperature). ΔE = m c ΔΘ

Change in energy = mass x specific heat capacity x change in temperature.

Required Practical 14 – Using the above formula, work out the specific heat capacity of a substance.

Power is the rate at which work is done, it is simply the work done in joules (or energy transferred) divided by the time taken in seconds. P=E/t

Finally, efficiency. This is a measure of how much of the energy put into s system is transferred into a useful store.

Efficiency = useful output/total input

#### Extra topics needed for the Higher papers:

Students sitting the higher paper need to describe ways of increasing the efficiency such as lubrication to overcome friction and prevent energy being wasted as heat.