How many helium-filled balloons would it take to lift a person? Assume the person has a mass of 80kg and that each helium-filled balloon is spherical with a diameter of 33 cm. ?

It is necessary 3815 balloons to lift a person of 80 kg

Explanation:

Knowing that

density of air ρa = 1.293 kg/m³

density of helium ρh = 0.1786 kg/m³

Each balloon has

V = πd³/6 = π(0.33m)³ / 6 = 0.0188 m³

So,

the "lift" for each balloon is

L = (ρa - ρh)Vg = (1.293 - 0.1786)kg/m³ * 0.0188m³ * 9.8m/s² = 0.2055 N

This way,

the number of balloons n = 80kg * 9.8m/s² / 0.2055N/balloon = 3815

causes

fossil fuels burn

cities become more industrialized

human population grows worldwide

the temperature in kelvin of 2.0 dm3 of an ideal gas is doubled and its pressure is increased by a factor of four. what is the final volume of the gas