How is energy measured

Read the section called "How do we measure energy?" and use the information you find to answer the following questions:

1) What units can energy be measured in?
2) Why have human beings decided that we need to measure energy?

Type your answers into you electronic ui books.

Now read the next section of the text and complete this sentence in your eui book...

Energy cannot be __________ and it cannot be ___________.

Write a paragraph in your eui book to explain what that means. Include examples of how energy changes from one form to another. Can you also include examples of where the energy came from each time?