What you will need:
- Food Saver ® vacuum seal food saver with hose attachment
- Food Saver ® canisters
- Air pump (with gauge)
- Empty one or two liter pop bottle
- Tire valve stem
- Marshmallow Peeps or regular mini marshmallows
- Whipped topping
- Adult supervision
1. Place your marshmallows, peeps or whipped topping in your container (or Pop bottle)
2. If using Food Saver, attach hose and turn machine on
3. If using pop bottle and air pump:
a) Drill a hole in the lid of the pop bottle so that you can properly insert the tire valve stem
b) Attach pump to valve stem.
c) begin pumping air into the bottle
CAUTION: DO NOT pump more than 70 PSI of air pressure into the bottle or it may explode causing serious harm or injuries.
What is going on?
The air around us has pressure! There is 14.7 pounds per square inch (PSI) of air pressure all around us. It is constantly pushing on every inch of our skin. By placing the peeps in the airtight canister and attaching the vacuum, you are removing air molecules and reducing the air pressure inside the container. As the air pressure is reduced, we can see the effect that it has on the soft marshmallow peeps as they begin to grow bigger. If we now let all the air back in the container, the air pressure is now increased back to 14.7 PSI and the peeps will again shrink. You may notice the they are all wrinkled looking due to the stretching that they just experienced.
By adding pressure to the bottle, you will now see the effect that more air pressure has on the marshmallows as the are reduced to about half of their original size!
Try other ingredients such as whipped topping or shaving cream. What types of objects will be effected more by the air pressure? What type of objects do not appear to change under various pressures?