Science+Project+15

OBSERVE: Pull down slowly on the stretched balloon. What happens to the balloon inside the cup? When you pull down slowly on the stretched balloon the tiny balloon expands. Because when you pull down the stretched balloon it forces air down through the straw inflating the tinny balloon with air. Also, there is more space for the straw to inflate the tiny balloon.

Push up on the stretched balloon. What happens inside the cup? When you Push up on the stretched balloon the tiny balloon shrinks inside because there is now less space in the cup so the small balloon deflates to match the cups volume.

EVALUATE: Is there more or less space inside the cup when you pull down on the large balloon? When you pull down on the large balloon there is a lot more space inside the cup.

IDENTIFY: When you pull the large balloon down, what fills the extra space in the cup? When you pull the large balloon down air fills the extra space inside the cup. Because when you pull down on the stretched balloon it pulls air down with it through the straw filling the small balloon.

COMPARE: How is the air pressure in the balloon similar to the air pressure in your lungs? Write down what you think happens when you breathe air into your lungs. When you inhale, your lungs fill with air, just like the small balloon does when you pull down on the large balloon. But when you exhale your lungs push out all the air built up in your lungs, the same thing happens when you push up on the stretched balloon.

Great job, Casey! You've thought this out well. How is the air pressure similar in both the model and your real lungs?