Question

A balloon filled with helium or hot air can float in the atmosphere. A balloon filled with air from your lungs falls to the ground when it is released. Why do these balloons behave differently?

Answer 1

Hint:Here we have to apply the concept of buoyancy. The relative densities of an object and the substance in which it is positioned decide whether it can sink or float. It can sink an object that has a greater density than the liquid it is in. An object that has a lower density can float than the liquid it's in.

Complete answer:
Buoyant force is an upward force exerted by fluids on some object that is placed in it. Buoyancy is called the power of fluids to exert this force. A fluid exerts pressure in both directions, but at a greater depth, the pressure is higher. Therefore, where the fluid is higher, the fluid underneath an object exerts more pressure on the object than the fluid above it.

Weight is a measure of the force of gravity pushing down on an object, when an object is held up by buoyant force. What force is greater decides whether an object is sinking or floating. Density, or the quantity of mass in a given space, is often attributed to an object's ability to float. That's how weight is influenced by mass. A denser material volume is thicker than the same volume of a less dense substance.

Fluids are air and gases, including water. Because of scale, all balloons are in a fluid but behave differently. The helium-filled or hot-air balloon is less dense than the air in the atmosphere. An item can float if it is less dense than the fluid. Since the balloon is denser than the air, the bubble packed with air falls steadily from the lungs to the ground.

Note:To displace a greater weight, a higher buoyant force is required, so an object has to displace more water by falling deeper into the water to balance its weight. A moving object displaces ample water such that the buoyant force equals the weight of the object.