# What will be the temperature difference needed in a hot air balloon to lift 1 kg...

• Nov 22nd 2008, 02:03 AM
fardeen_gen
What will be the temperature difference needed in a hot air balloon to lift 1 kg...
What will be the temperature difference needed in a hot air balloon to lift 1 kg weight if volume of balloon is 100 m^3 and temperature of atmosphere is 25 degree celsius and pressure is 1 atm. Neglect the mass of the material of the balloon.
• Nov 22nd 2008, 04:16 AM
fardeen_gen
Is there any formula for payload of hot air balloons?
• Nov 22nd 2008, 06:32 AM
HallsofIvy
Quote:

Originally Posted by fardeen_gen
What will be the temperature difference needed in a hot air balloon to lift 1 kg weight if volume of balloon is 100 m^3 and temperature of atmosphere is 25 degree celsius and pressure is 1 atm. Neglect the mass of the material of the balloon.

What are the weight of 100m^3 of hot air as a function of t? What is the weight of 100m^3 of 25 degree C air? The difference between those weights is the 'bouyant' force on the balloon. Set that equal to the weight of a 1 kg mass and solve for t.