NAME: _______________________________________ DATE: _____________ CLASS: ______________



Directions: Answer the questions below in the space provided.

1. Explain how work and energy are affected by power.



2. Using the equation for power, determine how much power in watts is involved if 300 joules of work are done in 10 seconds.



3. About how many times longer would a 10 watt lightbulb be able to burn compared to a 100 watt bulb with the same energy?



4. Rank the following items from lowest power requirement to highest power requirement.

 __________  a 100 watt lightbulb burns for 2 hours
 __________  a 40 watt lightbulb burns for 4 hours
 __________  a 1500 watt hair dryer is used for 0.5 hours
 __________  a 500 watt microwave operates for 0.5 hours
 __________  a 15 watt compact fluorescent light burns for 10 hours

5. Calculate how much it would cost to operate a 1000 watt spotlight for one 8 hours if 1 kilowatt-hour costs $0.15.



6. How do the lighting requirements differ between the hallway, the gym, and the library of your school? How would you suggest these areas be lit?


Created for the NTEP II program on behalf of the National Renewable Energy Laboratory in Golden, Colorado.