Buoyancy in Air

PHY 200 & 230

Loyd pre-lab #18 applies. Archimedes Principle and the standard textbook density of helium (corrected for current temperature & pressure) are used along with the experimentally determined mass and volume of a helium filled balloon to determine the density of air. Experiment can also be conducted or repeated with neon gas in place of helium if available.

Equipment

Notes

String should be roughly one arm's length (~1m) long. Also, please use the cheapest common white string. Balloons must be at least 12 inch diameter type.

The room must be equipped with a box of large and a box of small paper clips placed on the back counter, and there must be direct access to a helium/neon tank with balloon nozzle. An assortment of slotted masses, barometer, and thermometer should already be present in each room.
The following items should be put on the SMALL STAINLESS-STEEL CART in the room: small fish tank with attached pulley, three plastic water bottles, bucket of misc balls, crystal model (stiff spring), and Newton spring scale. The fish tank is in the demonstration room (JE-113A) and contains the three bottles, one empty, one with water, one with sand. Do not put water in the tank. Leave it dry for instructor to fill as desired.