Prelutsky+Poem+11

OBSERVE: Pull down slowly on the stretched balloon. What happens to the balloon inside the cup? The balloon expands. I think that air is filling the balloon. I think this because every time I stretch it the crinkles sowing were it is deflated disappear and push out. When you do this it is sucking air in through the straw and into the balloon. Push up on the stretched balloon. What happens inside the cup? The balloon grows thiner. It seems that the air is flowing out of the balloon. I know this because every time I do this the balloon seems to cling to the opposite side of the balloon. When you do this it forces the air out of the balloon becouse there is less room.

EVALUATE: Is there more or less space inside the cup when you pull down on the large balloon? I think that there is more space in the balloon. I think this because when you stretch the balloon it expands the rubber and allows more air to flow in and take up more room.

IDENTIFY: When you pull the large balloon down, what fills the extra space in the cup? When I pull the large balloon down air fills in the extra space. I think that some kind of suction force is pulling air in through the straw and allows it to flow into the balloon and extra space. Compare I think that when you breath air into your lungs they expand such as the balloon did. then I think that some force will push in on the lungs forcing the air back out through the windpipe or the straw as shown in the experiment.