Kidneys are a filter system. The main job of the kidneys is to remove waste from the blood and return the cleaned blood back to the body. Each minute about one litre of blood ï­ one-fifth of all the blood pumped by the heart - enters the kidneys through the renal arteries.
The volume of helium in the balloon has been estimated as being able to lift a total load, including the balloon material and the structure beneath it, of 65 pounds (29 kg) at sea level and 48 pounds (22 kg) at 8,000 feet (2,400 m).
Even when you add the weight of the ball itself, it is lighter than the amount of water that would fit in the same space. This is called buoyancy. Helium is even lighter than air. A liter (about a quart) of air weighs about 1.25 grams (much less than an ounce) â thatâs not very much. But a liter of helium weighs even less â only 0.18 grams (a tiny fraction of an ounce). A balloon thatâs 1 foot (30 centimeters) in diameter holds about half a cubic foot of helium, which is the same as 14 liters. This means the balloon will weigh about half an ounce (14 grams) less than the same sized balloon filled with air. So buoyancy goes to work, and just like the ball in the pool, the balloon floats upward. â¹ âº Ã Ã