Urban Ecology

Wind Speed

What it does

This experiment shows you how wind speed is measured.

What you need

• Pencil with eraser on top
• 4 small paper cups (5 ounce size)
• 2 drinking straws
• Straight pin
• Tape

What to do

1. Cross the drinking straws to make a "+" and tape them together in the center.
2. With the pencil, punch a hole into the side of each cup near the rim.
3. Press the end of a straw through the hole in each cup and secure it with tape.
4. Press the pin down through the center of the straws where they overlap.
5. Push the end of the pin into the top of the pencil eraser.
6. Hold the pencil upright and blow toward the cups. Alternate gentle and hard blowing.
7. If there is wind outside, hold the contraption outside and see what happens.

What it's all about

The cups will spin around from the force of the blowing air. A stronger wind will make the cups spin quickly. A gentle wind will make them spin slowly. The spinning cups are a simple version of a "Robinson anemometer." An anemometer tells you how fast the wind blows. The air fills the cups, pushing them forward. Wind speed is determined by counting how many times the cups rotate in a full circle per minute.

Remember, be sure you have a parent, teacher, or other adult help you!

How do scientists study air pollution?
Read about it.