Say the density of air is 1.23 kg/m3 and the density of heliumis 0.164 kg/m3 when both are at STP. Let's model a balloon as asphere of radius 0.12 m, with mass 2 g.
1) What is the mass of the helium that would fill a singleballoon?
2) What is the buoyant force on a single balloon?
3) What is the net force on a single balloon?
4) If we attach 0.5 m of string (properties: 800 feet weighs 1pound), what is the net force now on the balloon?
5) How many balloons would you need to have a 1 kg kitten inequilibrium, hovering just above the ground? (assume all of thestrings are vertical, this is actually another problem)
