This week in Physical science we will be finishing our discussion of gravity, then moving on to the topics of energy, work, and power. In common usage energy and power are often used to mean the same thing, but in science they mean two separate but related ideas: power is simply the amount of energy per unit time. This leads to a somewhat convoluted measure of energy on your electric bill, the kilowatt-hour, which is energy per unit time multiplied by time, thus leaving energy. Work in a physics sense is perhaps the most confusing concept to grasp, since one can exert a great amount of effort but do no work: for example, carrying a heavy box across a room does no work if analyzed at a basic level of physics.
For ten points of extra credit, students can answer the following question and turn it in by Wednesday:
Who is the unit of energy named after, and when was he alive?