Kids Advent Calendar: Day 4

This is the fourth day in my new kids advent calendar, An Experiment to RememberWe're using Christmas science activities to teach about Jesus!

Kids Advent Calendar

Lesson 4: Trust God's Signs


* cup
* index card or cardstock
* water

Step by Step Experiment:

1- Fill the cup up to about 1/8th an inch from the very top with water.

2- Place the card on top of the cup and hold it in place while you tip the cup upside down.

3- Carefully remove your hand and watch the card stay in place!

You may want to practice this in advance!

The Life of Jesus:

"Now when Jesus was born...there came wise men from the east...Saying, where is he that is born King of the Jews? for we have seen his star in the east, and are come to worship him."  -Matthew 2:1-2

The wise men trusted God's sign (the star) and followed it to Jesus.

It takes a lot of trust to let go of the card in this experiment!

How do you trust God's signs?

Science Explanation:

When you first tip the cup upside down the air pressure pushing up on the card is the same as the pressure of the water pushing down on the card. BUT, gravity pulls the water down JUST enough for the tiniest bit of water to escape. The little pocket of air inside the cup (not touching the card; at the "top" of the cup when it is upside down) expands to fill up the space left behind by the small amount of water that escaped. Since the same amount of air in the air pocket expanded, it now puts less pressure on the card than before the water escaped. NOW, the air pressure pushing up against the card is greater than the pressure pushing down and a seal forms between the card and the cup. If any air or water gets through that seal, it will change the balanced forces and water will spill! 

Also, water "sticks" to itself (cohesion and surface tension) and to the cup and card (adhesion) because of its molecule shape.

This is the lesson for Day 4 (of 25) in An Experiment to Remember, a kids advent calendar that uses science object lessons to discuss the life and teachings of Jesus.

Learn more about An Experiment to Remember HERE!

And if you're looking for more homeschool unit studies, be sure to check out our growing collection here!

Happy Educating,
Carla & the kids who don't sit still!