## Monday, August 3, 2015

### Natural Fluctuations in Alternative Energy: Effects of Variable Wind Speed on Turbine Output

Wind turbines are a popular form of alternative energy. Locating an area where the wind speed is high enough and reasonably predictable can be difficult, however.

What happens when wind speed is not constant? Consider the following graph, excerpted from The Science of Energy Efficiency, available from Schottenbauer Publishing.

Discussion Questions
1. What is the range of electric current from the wind turbine?
2. Considering the entire graph, what is the average electric current?
3. During what time span is the generation of electricity approximately the highest?
4. During the time span of highest current output, what is the range of current as it fluctuates?
5. What is the range of electric potential generated by the wind turbine?
6. What is the average electric potential during the time span of highest current output?

Over 8,000 graphs from Schottenbauer Publishing provide additional real-life topics for student learning, including sports, transportation, construction, environment, music, entertainment/toys, and general physics.

### Intensity of Light and Brightness

Conservation begins with efficiency. How bright does a light bulb really need to be? It turns out that the intensity of light is related not only to light bulb construction, but also to distance from the light bulb. Consider the following graph, excerpted from The Science of Energy Efficiency, available from Schottenbauer Publishing.

Discussion Questions
1. What does the horizontal axis represent? How does this variable affect the graph?
2. What is the intensity of light near the bulb?
3. What is the intensity of light at 36 inches?
4. Approximately what is the intensity of light at 48 inches?
5. Assuming a constant velocity of the measurement unit, approximately what is the intensity of light at 12 inches? 24 inches?
6. Redraw the graph as distance from light bulb (x-axis) versus intensity of light (y-axis).
7. Is the velocity constant in this graph, or is the probe slightly faster or slower on approach (compared to retreat)?
8. What is the range of natural distance for using a lightbulb in a typical home? Would this light bulb be sufficient for a reading light?

Over 8,000 graphs from Schottenbauer Publishing provide additional real-life topics for student learning, including sports, transportation, construction, environment, music, entertainment/toys, and general physics.