Unit 9: Work, Power, & Simple Machines

Learning Objectives:

PSc.3.1.3

• Explain scenarios in which work is done, identifying the force, displacement, and energy transfer- work requires energy; when work is done on an object, the result is an increase in its energy and is accompanied by a decrease in energy somewhere else.

• Compare scenarios in which work is done and conceptually explain the differences in magnitude of work done using the relationship W= F ∆d .

PSc.3.1.4

• Infer the work and power relationship: P = W/t = Fd/t = Fv

• Determine the component simple machines present in complex machines – categorize a wedge and screw as variations of an inclined plane; a pulley and wheel & axle as variations of a lever.

• Explain the relationship between work input and work output for simple machines using the law of conservation of energy.

• Define and determine ideal and actual mechanical advantage

• Define and determine efficiency of machines

• Explain why no machine can be 100% efficient.