I am in my car and have a helium balloon in the middle of car.  If I hit the gas, What happens to the balloon?
819561
Perhaps surprisingly, the ballon will move forward (relative to the car). There are two ways to see this. One is the principle of equivalence: acceleration is like gravity, and in this artificial gravity field (directed backwards) there is a buoyancy force on the baloon (it's lighter than air). Or you could say a pressure gradient, directed forwards, has to build up inside the accelerated car (to accelerate the air), and this pressure will drive the ballon forward (the pressure is just enough to keep the air accelerating with the car, but the balloon is lighter than the air it displaces so it gains an extra acceleration).
762603
When the person speaks, the helium in his lungs go into his mouth and out of his mouth and into the immediate space in front of it.\n\nWhen you hear his voice, it will have gone through a substantial amount of helium before going through air :)
807839
heat. As you heat the air inside the balloon, the thermally excited air will escape from the bottom hole. Now the balloon is filled with less air and is there fore less dense.
412631
A balloon filled with hot air rises because of the force of buoyancy. That means the density of air inside is lesser than the surrounding air (because hot air expands thus density decreases) and thus there is an upthrust acting on the balloon. Now, if the surrounding air is at the same temperature then its density is same as that inside the balloon and so the balloon will not rise. But the balloon will not not remain at the same point. it will fall because of the weight of the rubber in it.\n    In case of exploration on other planets, firstly other planets have very low density of air in the atmosphere (most of them do not have any air) and secondly even then is one wants to use this one has to heat up the balloon to a temperature for which the density decreass lower than the surrounding. Hope this answers your question.
147395
A gas burner heats air inside the balloon and as the air becomes warmer it becomes less dense or lighter per unit of volume, compared to the surrounding air. The differance in the two air densities causes the balloon to float like a cork in water.  This is the reason balloonists launch their ballonons in the early morning when the air tempature is cooler.  The cooler the  outside air the less heat is needed in the balloon to get it off the ground saving fuel for a longer flight.
240987
put the opening of the balloon on the spigot of the helium tank.  they are usually made of rubber.  when you tip the spigot to one side, helium comes out.
164770
Helium is an inert gas, but will it react with oxygen in a high-pressure atmosphere? (I'll assume not.) If not, then I'm going to use Dalton's Law of Partial Pressures to say that the total pressure of the mixture = the sum of the partial pressures of each gas, and that the partial pressures inside the tank will be a ratio of what they were outside. \n\nNow, from your question, we have that 46L of He is being pumped into a tank with 12L of O2, or a total of 58L of gas is being squeezed into a 5L tank. As the 58L of gas is at 1 atm, I'd have to guess the total pressure of the gas can be found by examining the proportions:\n\nP1 = 1 atm\nV1 = 58L\nP2 = ?\nV2 = 5L\n\nP1*V1 = P2*V2\n(1 atm)(58L) = P2*(5L)\n11.6 atm = P2 (total pressure in the tank)\n\nAgain, I'm guessing that the partial pressures inside the tank are a ratio of what they were outside, meaning:\n\nHe:\nV(He)/V(total) = P(He)/P(total)\n46L/58L = P(He)/11.6\n11.6*(46/58) = P(He)\n9.2 atm = P(He)\n\nP(O2) = 11.6 = 9.2 = 2.4 atm\n\nIt's been a long time since I've had a chemistry course, but I have a few old textbooks here that are (somewhat) refreshing my memory.
414472
HAHAHAHA You all forgot about our little friend called drag! Inside or out the ball has a drag force acting on it by the surrounding air. Like stated before the air in the car is moving with you, and the car, and the ball all the same and the drag force on the ball at this point is negligible. This is not the effect of a vacume, a vacume is the absence of air. is it possible for there to be no air in the car? NO, Sooo.. outside on a bike or where ever, you are traveling at a speed where the balls light weight will be significantly affected by this drag force and it will cause it to slow down as you throw it up and while you keep riding on un affected by the static(motionless) air, your ball only has one force acting on it, air drag causing it to slow behind you.   test this by throwing a variety of same shaped objects while riding and you will see that the one with the most density will keep up the best. try a marble V.S. a ping pong ball.  then do it in the car
937535
The helium is compressed when it is in the tank.  When it exits the tank, it expands in the balloons until it equalizes with atmospheric pressure.  Any gas can be compressed, as to occupy a smaller volume.  You can see this if you would take a plastic container fill it with air, and submerge it to the bottom of a swimming pool.  you would able to see that the container would deform because of the volume change of the container.
196284
Take a quick sip of it and that air comes out when you speak.\n\nDon't try to do it a bunch of times in a row though. There's no oxygen in helium so i passed out once trying to do it for too long.
1035826
Some novelty balloon are as large a 6 foot in diameter. But we will assume that you are dealing with a 1 foot diameter 300mm balloon. \n   Also the ambient temperature plays a role so we will assume you are about halfway between equator and north pole on an average summer day say 70 degrees Celsius.\n  Wind speed we will negate, as you will pick an absolutely calm day.\n  Thus you have two fundamental forces that of gravity on the balloon. And the lift caused by a difference of atomic weight of the helium vs air. \n  Then one must run tests to determine at what circumference the novelty balloon will burst, and the air pressure at various elevations.\n  We will assume the balloon can double in volume before exploding  and that air pressure goes down geometrically as the balloon rises (this is not true by the way) (some balloon will pop before others and air pressure vary's from day to day area by area etc.)\n Using all these estimated averages I predict that your balloon will reach a height of 5 kilometers before bursting.\n  However experience in the field has shown me that they usually rise so gradually that they first develop a slow leak and then float gently back to earth as they lose their helium.\n  There they are frequently eaten by some poor animal who dies as a result of your experiment so please do not do this at home Thanx
804421
The higher the balloon goes in the atmosphere the less pressure on the balloon. This causes the helium to expand its volume. If the balloon was filled to capacity it would *pop* at higher altitudes.
797306
Lets look at gas in a balloon.  Lets pretend we can see the gas molecules buzzing around on a micro-scale.  At the boundary of the gas and the surface there are always some of these molecules hitting the surface.  The molecules hitting the surface, much like you pushing on a surface, creates the pressure.  So, the faster the molecules are traveling (due to a rise in temperature) the harder they will impact the surface.  Also if there are more molecules present, more will be hitting the surface and also increase the pressure.  This can be verified by analyzing the ideal gas law, PV=nRT.  Where P=Pressure, n=amount of gas molecules, and T=temperature.  We can see if we raise the n or T the pressure must rise also, assuming a constant V(volume).\n\nOn a macro-scale, such as our atmosphere, the gas has a mass just like anything else.  Although the mass is small, there are miles of gas so the total mass has a noticeable affect here at the ground.  We don't notice the pressure because we are used to it (sometimes you may notice it when your ears 'pop' driving up or down a large hill) but the atmosphere is exerting pressure on everything.
1076536
Weather balloons fly many miles high.  At the ground they look like very loose bags, but they expand and fill out as the balloon goes higher.  A balloon will rise as long as the wieght of the gas in the balloon is less than the weight of the air it displaces.  Eventually a balloon reaches a point where the air it displaces weighs the same as the gas inside of the balloon, the balloon can't expand further, and it ceases to rise any further.  \n\nIt may not pop, but just reach a position of equillibrium.  It will pop only if the pressure of the gas inside the balloon exceeds the strength of the balloon before the point of equillibrium is reached.
856659
Helium is a lighter gas than the nitrogen/oxygen that our atmosphere is composed of, so a helium balloon will naturally float up.  It pops because the gas inside the balloon expands as the balloon rises to higher altitudes where the air pressure is lower.
4088
because the air inside the car is moving with the car
372306
Depends on how much helium you put into it, and how big your baloon is, and how and where you release it, and... it may well heep going up and up and up to the top of our atmosphere if you put enough in.