Science Smarts: Wind speed

By PATTY ROOKS on February 18, 2022.

I do not know about you, but that wind could go away. It has been exceptionally windy the past few weeks.

There has been damage all over – I’ve even seen a trampoline on someone’s fence. I am going to say that is not where it should be! Well, there really is not anything you can do about the weather, but it has made me think, how can you measure wind speed? Well, let’s get started!

Remember to ask an adult before doing this experiment

Materials

• 5 small paper cups

• 2 straws

• Tack

• Good heavy masking tape

• Pencil (with a new eraser)

• Hand held hole punch

• Permanent marker

• Scissors

• Ruler

• Stopwatch

Procedure

• Take one of the cups and using the ruler measure 1.5 cm below the rim. Put a mark here. Repeat with three more cups.

• Using the hole punch, punch a hole at each mark. Set aside.

• With the final cup, measure 1.5 cm below the rim and mark it. On the opposite side of the cup, repeat.

• Still using the final cup, measure 1 cm below the rim and mark the spot. Repeat on the opposite side of the cup. You should have four marks on this cup.

• Using the hole punch, punch holes in each of the four marked spots.

• Carefully push the pencil through the bottom of the cup. Set aside.

• Take one of the cups with just one hole in it.

• Carefully slide the straw through the hole in the cup. Bend about 1cm of the end of the straw in the cup and tape it well.

• Repeat for the other three cups.

• Place the other end of the straw through two of the holes in the fifth cup and then trough the hole in one of the other cups. Tape the end of the straw to the inside of the cup as you did earlier, making sure that the openings of the two cups face opposite directions.

• Repeat, sliding the straw through the remaining two holes in the cup.

• Make sure the opening of each cup faces the bottom of the cup next to it (in other words, no two openings should be facing each other). Each of the four cups should be facing sideways.

• Insert the pencil with the eraser facing up through the bottom of the fifth cup. Carefully push the tack through the two straws and into the eraser on the pencil.

• Mark an X with your marker on the bottom of ONE of the cups.

• You are ready to measure wind speed!

• Find a windy location.

• Watch the bottom of the cup as it spins around (the number of revolutions). You need to be able to see the “X”.

• Count the number of times the “X” goes by in 10 seconds.

Your estimated wind speeds are as follows:

2-4 revolutions ~ 2km/h

5-7 revolutions ~ 3 km/h

10-12 revolutions ~ 6km/h

19-21 revolutions ~ 11 km/h

30-32 revolutions ~18 km/h

41-43 revolutions ~ 24 km/h

50-51 revolutions ~ 29 km/h

Explanation

In this experiment you made a very simple wind speed anemometer. An anemometer is a device used for measuring wind speed, and is common weather station instrument. The number of revolutions in a given time period will allow you to calculate the approximate wind speed.

Now if by chance, it is not windy out (which I highly doubt!), use a hair dryer to test out your anemometer.

Do not forget about our Science Challenge each and every week in February! Some great prizes to be won. Visit the Science Fair website @ HYPERLINK “https://www.seab-sciencefair.ca/” seab-sciencefair.ca for all the details.

Patty Rooks, Senior Scientific Consultant PRAXIS, “Connecting Science To The Community”. Contact Praxis at praxis@praxismh.ca, http://www.praxismh.ca, Tweet or follow us @PraxisMedHat, or friend us on Facebook. Address: #12 826 11 Street S. E., Medicine Hat, Alberta, T1A 1T7 Phone: 403.527.5365, email: praxis@praxismh.ca.

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