Helium
Put a straw in the end of it and blow into the balloon. That should make it fly straight although make sure you don't use helium and make sure there is as little of wind around as possible. From Matthew
smd
Attaching weight to a balloon increases its overall mass, which can make it harder for the balloon to generate enough lift to fly. The amount of weight you attach must be carefully considered to ensure that it does not exceed the balloon's lifting capacity.
air is heavier than balloon, air rises
balloon
Yes, you can make a balloon fly using propellers or an electric motor to provide thrust. By attaching a propeller or motor to the balloon, you can create lift and propulsion to make it fly without the need for hot air or helium.
u fly ;)
The hot air inside the balloon expands, making the hot air balloon fly.
it'll make it fly up
Ballons
Helium gas is typically used to fill balloons to make them float or fly. Helium is lighter than air, so it causes the balloon to rise due to the difference in density between the helium gas inside the balloon and the surrounding air.
Hot air balloons use the fact that hot air rises as a way to make balloons fly. When the air inside the balloon is heated, it rises, and this creates lift which is used to make the balloon fly.