Calculating Hot Air Balloon Volume & Lift

Thread starter Desperate
Start date Apr 23, 2021
Tags

Air Balloon Constant speed Hot Lift Temperature Volume

Click For Summary

The volume of the hot air balloon is calculated using the formula V=((4/3 pi R^3)/2) + (1/3 pi h (R^2 + r^2 + Rh), resulting in 2956.24 m³ with R=9m, h=15m, and r=1m. The balloon's mass is 750 kg, and at a height of 5000m with a temperature of 373 K, the pressure changes from p1 = 101300 Pa to p2 = 50650 Pa. The lift force is determined to be F = mg - 7350 N. Clarification is needed regarding the statement about not exceeding the temperature of the air inside by 100 degrees Celsius, as it is currently vague. Accurate calculations and clear parameters are essential for understanding hot air balloon dynamics.

Apr 23, 2021

Desperate

Homework Statement: We have to make a hot air balloon that can rise up to 5km and bring up 4 people. In total, the balloon weight is 750 kilogrammes. We cannot exceed the temperature of the air inside by 100 degrees C. We have to find how the temperature of air must change in order for the balloon to maintain a constant rising speed.

Relevant Equations: Fl = V (ρc - ρh) ag

Volume of hot air ballon
V=((4/3 pi R^3)/2) + (1/3 pi h (R^2 + r^2 + Rh) = 2956.24 m3

Balloon:
R=9m
h=15m
r=1m

m = 750 kg
H = 5000m
T = 373 K
p1 = 101300 Pa
p2 = 50650 Pa
M(air) = 0.029 kg/mol
F = mg - 7350 N

Physics news on Phys.org

Apr 23, 2021

phinds

Science Advisor

Insights Author

Gold Member

2024 Award

You need to show more of an attempt at working this out. Also, "We cannot exceed the temperature of the air inside by 100 degrees C" is an ambiguous statement. Please clarify.

Thread 'Coulomb's force vs the Lorentz force'

Beams of electrons and protons move parallel to each other in the same direction. They ______. a. attract each other. b. repel each other. c. neither attract nor repel. d. the force of attraction or repulsion depends upon the speed of the beams. This is a previous-year-question of CBSE Board 2023. The answer key marks (b) as the right option. I want to know why we are ignoring Coulomb's force?

View full post »