Energy sources, conservation and efficiency

Convincing your students that the total amount of energy in the Universe is fixed and that what there is cannot be destroyed and that no more can be created is at odds with their everyday use of the concept. You may find this guidance interesting and useful to begin discussions with your class.

The resources below provide examples of situations where energy is transferred or transformed and the total energy of the system (considering losses) is constant. Most of these are set in a real world rather than a classroom context but should make it clear that it is important to be able to measure useful energy, wasted energy and to calculate the efficiency. The SEP energy meter (first link) is one of the best ways to measure efficiency in class easily although the experiment for measuring specific heat capacity is another option where you give the class the value of the specific heat capacity of an object and they work out the energy loss from the difference between E=ItV and E=mcΔT.

Being able to make calculations of the energy changes associated with changes in a system, recalling or selecting the relevant equations requires use of math skills.

Whilst this list provides a source of information and ideas for experimental work, it is important to note that recommendations can date very quickly. Do NOT follow suggestions which conflict with current advice from CLEAPSS, SSERC or recent safety guides. eLibrary users are responsible for ensuring that any activity, including practical work, which they carry out is consistent with current regulations related to Health and Safety and that they carry an appropriate risk assessment. Further information is provided in our Health and Safety guidance.