How to calculate the force exerted by pressure on hot air balloon envelope fabric? [closed]

How to calculate the force of hot air balloon envelope fabric? and how to select a fabric which can bear this force? For example, a spherality balloon:

• $r=10~m$
• $T_1=100~°C$
• $ρ_1=0.95~kg/m^3$
• $T_2=20~°C$
• $ρ_2=1.25~kg/m^3$
• $m=1000~kg$

Where:

• $r$ is the radii of the balloon, in m
• $T_1$ is the temperature of balloon inside atmosphere, in Celsius
• $ρ_1$ is the density of the balloon inside atmosphere, in kg/m3
• $T_2$ is the temperature of balloon outside atmosphere, in Celsius
• $ρ_2$ is the density of the balloon outside atmosphere, in kg/m3
• $m$ is the total weight of the balloon(including balloon all equipment and persons)

closed as off-topic by Federico♦, Thunderstrike, Simon, fooot♦, Ralph JFeb 22 '16 at 18:19

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "This question does not appear to be about aviation, within the scope defined in the help center." – Federico, Simon, fooot
If this question can be reworded to fit the rules in the help center, please edit the question.

• Hi! As this stands it sounds like you're trying to get us to do your homework. Could you perhaps elaborate what you have tried to do to solve the question on your own? You're also best of splitting this question (forces/materials) into two separate ones. – Thunderstrike Feb 22 '16 at 12:15
• This looks more like a physics homework than anything else. – Federico Feb 22 '16 at 12:25
• – ROIMaison Feb 22 '16 at 13:05