Lesson 2 Work and Energy
Completion requirements
Introduction
Did you know that work is a form of energy?
C2.1 45 pound weight being lifted
You should recall from previous studies that force is a push or pull. Think about how much force you would have to exert to lift a 20 kilogram weight from the ground to above your head. How does force relate to work and energy? What if I
told you that you would have to do no work to hold that weight above your head once it is there? Does that sound right?
Targets
By the end of this lesson, you will be able to
-
recall, from previous studies, that force is a push or pull and that work is energy used to increase the speed of an object or move an object against a force
-
calculate
«math xmlns=¨http://www.w3.org/1998/Math/MathML¨»
«mi»W«/mi»
«mo»=«/mo»
«mi»F«/mi»
«mi»d«/mi»
«/math» and show that a change in energy is equal to work done on a system:
«math xmlns=¨http://www.w3.org/1998/Math/MathML¨»
«mo»§#8710;«/mo»
«mi»E«/mi»
«mo»=«/mo»
«mi»W«/mi»
«/math»
- derive the «math xmlns=¨http://www.w3.org/1998/Math/MathML¨» «mi»SI«/mi» «/math» unit of energy and work, the joule, from fundamental units and explain where the joule comes from