Answer:
Gas makes things buoyant by making the volume of an object lighter than the surrounding fluid it is trying to displace.
Gas Buoyancy is useful in the following ways;
• Airships
• Steel ships and
• All floating and flying vessels
Explanation:
Buoyancy is the tendency of an object to float in a fluid such as air or water. It is a phenomenon that was theorized by the mathematician, Archimedes known as the Archimedes Principle.
It states that the upward buoyant force that is exerted on a body immersed in a fluid is equal to the weight of the fluid that the body displaces.
The principle explains the reason why objects float and fly.
So, when an object is immersed in a fluid, it can float due to the upward force exerted by the fluid on the object. But for this to happen, the object has to weigh less than the fluid it is displacing.
This is where the use of a gas comes into play.
Because the object may be heavier than the surrounding fluid it is trying to displace, it is filled with a large amount of gas (usually hydrogen and/or helium) which is lighter. This makes the volume of the gas and the object put together lighter than that of the surrounding air.
This is what causes objects to float or fly