You may have been fascinated by helium balloons as a child and begged your parents to buy you one at a circus or a fair. If you hold its string, it will float above you. But, if you let go, it will fly away until you can no longer see it.
Well, helium balloons work in the law of buoyancy. With the presence of gravity, all gases and liquids exert an upward force, regarded as buoyancy, towards any material immersed or submerged in them. If the object displaces the gas or liquid is lighter or less dense, the upward force will force it to float. For instance, styrofoam floats in a pool of water because it is less dense than water.
Helium balloons, in this case, are immersed in the pool of air around us. But, Helium is a lot lighter compared to the air around it, weighing only 0.1785 grams per liter. On the other hand, Nitrogen, which composes 80% of the air we breathe, has a standard weight of 1.2506 grams per liter. Thus, allowing Helium balloons to float through the upward force of buoyancy.
Now, as helium balloons float, they possess its own lifting force. The lifting power of bargain balloons is calculated at around one gram per liter, which means if you have a balloon that is filled with 4 liters of Helium, then it can lift 4 grams.
The regular helium balloon at a circus or fair typically is around one foot or 30 meters in diameter. To calculate how many liters it can hold, we must use the equation 4/3 x pi x r x r x r.
Determine the radius first. A Helium balloon with a 30-centimeter diameter will have a radius of 15 centimeters. Applying it in the equation, then, we will derive 14 liters.
With that, a standard Helium balloon at a circus or fair, given that the balloon’s weight and is negligible has a lifting force of 14 grams.
So, if a person has a weight of 80 kilograms or 196 pounds, he or she will weigh 80,000 grams. As we know that a regular Helium balloon has a lifting force of 14 grams, divide 80,000 by 14, then it will need 5,714.28 balloons with a total of 80000 L of Helium to lift than person up! However, that’s the minimum, and adding 500 more is advisable to raise that person at a decent height. So, it will need around 6,200 balloons actually to lift a person.
For instance, instead of getting balloons at a circus of fair, the person instead went to a military surplus store and bought 10-foot or 3-meter balloons. Using the same equation, the army balloon can lift 14,000 grams, so it will need six of those balloons to lift the person up.
Meanwhile, a ballon that is around 100-feet or 30 meters in diameter can lift approximately 14,000 kilograms. Having one can quickly allow a person to float in a breeze. If ever you’re enticed of the idea, don’t as that is something we will never recommend trying for your own safety.