Energy change matrices

Communication skills: Organize and depict information logically

Individually: In this activity you will identify some machines in terms of energy changes.

We can represent energy changes using a simple matrix like the one below. One example has been completed to give you the idea. A light bulb is a device for changing electrical energy to light energy, so we begin with the row for 'electrical’ energy and then move across to the column for 'Iight’ energy, and write ’Iight bulb’ in the corresponding square.

Notice the arrow in the top left corner of the matrix. This tells us the direction of the energy change.

The diagonal cells from top left are filled in since no energy change would be achieved by objects in those boxes.

1 Identify and complete the table by writing energy changers in the empty cells. See the attached file.

2 Explain why it would have been incorrect to write 'Iight bulb' in the first box of the second row.

3 Does the matrix enable us to show all the energy changes taking place in these machines or processes? Explain your answer. Identify and state what other energy changes might be taking place in each of the machines or processes you have selected.

4 Now design your own matrix using three different energy forms. Test your friends by asking them to identify the energy changes and complete your matrix!

Assessment opportunities

In this activity you have practised skills that are assessed using Criterion A: Knowing and understanding.