Act_1 - Name Section Activity 1 Introduction to Physics 104...

6/13/05
1
Name _________________________ Section ___________________
Activity 1: Introduction to Physics 104
1.1 Review of Ratio Reasoning and Efficiency
Your instructor will review ratios and the efficiency of energy processes.
1) Efficiency of light bulbs Compare the relative efficiencies of an
incandescent bulb and a compact fluorescent bulb.
a) Using a wattmeter, measure the power required by an incandescent bulb. ______
b) Measure the power required by a compact fluorescent bulb. _______
c) Measurements have shown that each of these bulbs produce 3 watts of
visible light. Calculate the efficiency of the incandescent bulb.
d) Calculate the efficiency of the compact fluorescent bulb.
e) How do the efficiencies of the bulbs compare?
f) Group Discussion Question: Why is the compact fluorescent bulb so much
more efficient than the incandescent bulb?
2) Generating electricity with the exercise bicycle
a) If five 50-watt bulbs are lit, how many kilowatts of electricity are generated?
b) If you ride the bicycle and generate this much electricity for 8 hours, how
many kilowatt hours of electricity have you generated?
c) If you sold the electricity you generated for $0.10/kWh, how much money
would you receive for it?

6/13/05
2
1.2 Linear and Exponential Growth Rates and Exponential Decay
Your instructor will discuss linear and exponential growth and exponential decay.
3) Illustrating exponential decay
Roll the 20 dice in the plastic cup onto your table and remove any dice that land
with a “1” showing. Repeat for 20 throws, each time removing any dice showing
a “1.” After each roll, record below the number of dice left after you remove the
dice showing a “1.”