Question

A mountain-climber friend with a mass of 74 kg ponders the idea of attaching a helium-filled balloon to himself to effectively reduce his weight by 25% when he climbs. He wonders what the approximate size of such a balloon would be. Hearing of your physics skills, he asks you. Share with him your calculations that find the volume of the balloon.

Answer 1

`V=16.65 m^3`

Step-by-step explanation:

The volume of the balloon can be find compared the force in each cases so:

reduce 25% from 74kg

`R=(25)/(100)*74kg=18.5kg`

So the net force uproad on the balloon is

`F_b=18.5kg*g`

Now the density of the both gases air and helium are different however the volume is the same change offcorss the mass so:

`P_h=(m)/(V)=0.179 kg/m^3`

`P_A=1.29 kg/m^3`

`F_b=F_A-F_H`

`F_b=m_a*g-m_h*g`

`m=P/V`

`18.5kg*g=(1.29kg/m^3-0.179kg/m^3*)V*g`

`V=(18.5kg)/((1.29-0.179)kg/m^3)`

`V=16.65 m^3`