1. Key Concepts  When is work done on an object?  How do you determine the work done on an object?  What is power? Key Terms  Work  Joule  power

2.  Ideas

3. Scientific Meaning of Work - When a force moves an object.  Work = Force X Distance  W=F x D  The distance the object moves must be in the same direction as the force applied.  Force is measured in newtons  Distance is measured in meters  Work is measured in newton-meter or joules  Ex. an apple weighs about 1 newton. If you move it 1 meter you have done 1 joule of work

4.  If you lifted an object weighing 200N through a distance of.5m, how much work would you do?  A 600 N woman lifts a 100 N suitcase a distance of.5 meters. How much work did she do on the suitcase?

5.  Ideas

6.  Power - the rate at which work is being done,  or the amount of work per unit of time.  Power = Work = Joule = watt (W)  Time sec  Power = Force X Distance = watt (W)  Time  1000 watts = kilowatt - used to measure large amounts of power

7.  A motor exerts a force of 12,000N to lift an elevator 8.0m in 6.0 s. What is the power of the motor?  A crane lifts an 8.000 N beam 75m to the top of a building in 30 s. What is the crane’s power?