Doppler 9&10 STEM: Water V.S. Gravity

Teachers & Parents:

Does your kid have a science question?

Have them send us a video with a weather question to weather@9and10news.com!

Today’s experiment is another fun and easy one! Today we are looking at how forces work in the world around us.

The first question before we start, what is a force?

A force is a push or pulls on an object. So if you roll a ball across the floor you are applying a force to it. Gravity is a force that is always acting on the earth and everything on it

So here is what you will need for today’s experiment:

• A Glass
• Water
• Cardstock or Thin Cardboard

Procedure:

1. fill your glass to the very top with water. The type of glass doesn’t matter but you can experiment with different shaped glasses to see if it has the same effect!
2. Take your cardstock paper or thin cardboard and cut it to be roughly the size of the rim of the glass.
3. Place the cardstock paper cut out and place it on top of the glass filled with water and get ready for the magic!
4. Place your hand on the cardstock to hold it in place and flip the glass upside down.
5. If you are feeling brave, remove your hand but leave the paper. The paper should remain stuck to the underside of the glass!

Here is what happens:

When you place the cardstock on top of the glass and flip it over, the water will rush down and apply 2 forces.

1. It will apply a downward force on the paper, thanks to gravity
2. It also such the paper up, creating an airtight seal.

At the same time, the air around the cup is pushing up on it and will help to push the paper up against the rim of the glass even though the force of gravity is pushing down on it.

Creating a balance of forces!

You can try this experiment at home and test to see if different sized glasses create the same result. You can also try different materials instead of paper, like plastic or fabric!

If your kiddos try this experiment, send us photos of you and your experiment and you might get to see it during weather on The Four on Tuesdays!

Make sure you tune in every Tuesday for a New 9&10 STEM. Send us an email at  or find us on Facebook and at Doppler 9&10 Weather Team if you have a weather question or want something in science explained! It does not have to be weather-related! Anything Science or math-based we’ve got you! You can always get the latest forecast on 9and10news.com/weather as well as interact with us on social media!

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