Question on lifting power of gases

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    Gases Lifting Power
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SUMMARY

The discussion centers on the lifting power of gases, specifically helium-filled balloons. When half of the helium is removed from a rigid balloon without changing its weight, the buoyant force remains constant as it depends on the volume of air displaced. However, the load the balloon can lift increases by the weight of the removed helium. The concept emphasizes that the lifting power is determined by the buoyant force and the weight of the balloon's contents, not the gas inside.

PREREQUISITES
  • Understanding of buoyancy and Archimedes' principle
  • Knowledge of gas laws, particularly relating to density and pressure
  • Familiarity with the properties of helium and its applications in buoyancy
  • Basic principles of rigid structures and material science
NEXT STEPS
  • Research Archimedes' principle in detail
  • Explore the properties of helium and its behavior under varying pressures
  • Investigate materials suitable for creating lightweight, rigid balloons
  • Study the implications of gas laws on buoyancy and lifting power
USEFUL FOR

Students in physics, engineers working with buoyant systems, and hobbyists interested in balloon design and aerodynamics will benefit from this discussion.

Yapper
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take a balloon filled with helium if you where to make the balloon rigid, without changing its weight, then suck half of the helium out of it. would the balloon, with the same volume but different density, have more lifting power?
 
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What produces the "lifting power" is the buoyant force due to the air pressure acting on the balloon. That buoyant force depends on the volume of air displaced, not on what's inside the balloon. But the load that the balloon can lift is reduced by the weight of the balloon material plus whatever is inside the balloon. So by removing some helium, the balloon can lift an additional load equal to the weight of that removed helium. (Even better would be to remove all the helium! Realize that this is a thought experiment only--lightweight, rigid balloons that can withstand atmospheric pressure while containing a vacuum are hard to come by. :wink: )
 

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