Suppose that a party balloon is spherical, has a radius of 16 centimetres and is filled with helium. Furthermore suppose that we do our experiment under standard atmospheric conditions, when the air density is ρ=1.225kg/m3 . How many of these balloons should a 75 kilogram human carry in order to become airborne?

Question

Suppose that a party balloon is spherical, has a radius of 16 centimetres and is filled with helium. Furthermore suppose that we do our experiment under standard atmospheric conditions, when the air density is  ρ=1.225kg/m3 . How many of these balloons should a 75 kilogram human carry in order to become airborne?

oobleck · Accepted Answer

you want the volume to displace 75 kg of air. So, that would be 61.22 m^3 of air Using PV=kT, with P=1, pick a reasonable temperature and find V