During the video clips Prof. kstra posed the question: "How many helium party balloons could you safely carry before getting airborne?" This is exactly what we will find out now!

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 1.225 . How many of these balloons should a 75 kilogram human carry in order to become airborne?

Answer 1

4178

Answer 2

How do you find this number?