How many regular-sized helium-filled balloons would it take to lift someone?
Here’s how you could figure it out… If you have read the article How Helium Balloons Work, then you know that helium has a lifting force of 1 gram per liter. So if you have a balloon that contains 5 liters of helium, the balloon can lift 5 grams. A normal balloon at an amusement park might be 30 centimeters (about 1 foot) in diameter. To determine how many liters of helium a sphere can hold, the equation is 4/3 x pi x r x r x r. The radius of a 30-centimeter-diameter balloon is 15 centimeters, so: 4/3 x pi x 15 x 15 x 15 = 14,137 cubic centimeters = 14 liters So a normal amusement park balloon can lift about 14 grams, assuming that the weight of the balloon itself and the string is negligible. If you weigh 50 kilograms (about 110 pounds), then you weigh 50,000 grams. Divide your 50,000 grams by the 14 grams per balloon and you find that you need 3,571.42 balloons to lift your weight. You might want to add 500 more if you actually
