Question

an inflated balloon can not go up after certain level because

Answer 1

because of density of air in it......and density of that lvl......
hope helped

Answer 2

DENSITY is a physical property of matter, as each element and compound has a unique density associated with it. Density defined in a qualitative manner as the measure of the relative "heaviness" of objects with a constant volume. For gases the density may vary with the number of gas molecules in a constant volume.

Density Comparison to Air: The density of several gases is compared to the density of air. Does an object float in air or sink in the air? If an object containing a gas floats on air, it is less dense than air vs. if it sinks, it is more dense than air.

The balloon flies upwards for the same reason boats float on water. The weight of the helium is less than the same volume of air that otherwise would have taken up that space. So the weight of that volume of air - the weight of the balloon + helium is the lift produced.

The pressure in the balloon at sea level is the same as the pressure (slightly more actually due to the latex making up the balloon) of the air at sea level. As the balloon rises up in the air the air gets less dense. And since the pressure in the balloon is now greater the helium wants to take up the same volume as the air outside in the same volume. As the only thing keeping the helium inside the balloon is a flimsy layer of latex the balloon expands. The balloon expands and expands as the pressure decreases. Eventually the latex cannot take the stress and pops.