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# The Coriolis Effect (Grade 3)

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## The Coriolis Effect

Have you heard that in the southern hemisphere the water in a toilet flows differently? Some people think that when you flush a toilet, the water flows clockwise instead of counterclockwise. They'd be disappointed to learn that this is just a rumor. How the water flows in a toilet has more to do with the design of the toilet than where it is located. Still, there is actually a little bit of truth to the rumor.

In 1835, a French engineer by the name of Gaspard Gustav de Corilolis described something called The Coriolis Effect. The Coriolois Effect describes the curved path of moving objects. Bodies of water, like those found in a toilet are too small to be affected by the Coriolis force. However, the force can have a major impact on other moving objects.

For example, in the northern hemisphere, a hurricane's winds move counterclockwise. In the southern hemisphere, its winds move clockwise. The Coriolis force pushes the wind. This helps it move in a particular way. The harder and faster the wind, the more you can see the Coriolis Effect.

To understand the Coriolis Effect think of a ball being rolled across a spinning merry-go-round. As the ball moves across the merry-go-round it will arc and change position. This happens based on the direction in which the merry-go-round is moving. However, a person (or force) can come along to try and push the ball in another direction.

In the same way, the Coriolis Effect helps push the position of the wind and water in a different direction. It is based on how the Earth is rotating. Sometimes it's hard to notice. This may be because the wind and water aren't moving very fast. Other times, it's very clear that the Coriolis Effect is at work.

Even though the water in a toilet doesn't flow clockwise or counterclockwise because of the Coriolis Effect, it's good to know that the rumor is based in science. Perhaps one day someone will create a toilet in the southern hemisphere large enough to demonstrate the Coriolis Effect. Of course, it wouldn't be good for much else.
1.
Which way does a toilet flow in the southern hemisphere?
1. Clockwise
2. Counterclockwise
3. It depends on the toilet
4. Both ways at once
2.
Why did the author most likely write this piece?
1. To clear up a common rumor
2. To explain the Coriolis effect
3. To describe a ball on a merry-go-round
4. To sell toilets in the southern hemisphere
3.
Why doesn't Coriolis Effect have an impact on the water in toilets?
1. The water comes from a different source.
2. They are indoors.
3. Toilets have small bodies of water.
4. The pipes change the flow.
4.
Why is the Coriolis Effect especially noticeable during hurricanes?
1. Because hurricanes involve a lot of water
2. Because hurricanes come with hard and fast winds
3. Because hurricanes stir up a lot of sand
4. Because hurricanes get more attention than other storms
5.
The author provides the example of the ball on the merry-go-round to describe the Coriolis Effect. What other text feature would help readers understand the effect?
1. A diagram of how the Coriolis Effect works
2. A picture of a hurricane moving
3. An image of water in a toilet
4. Another description like the merry-go-round
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