If Emeka is standing on a flat, open field and holds a helium-filled balloon on a string and then lets go of the string, what happens to the balloon and why does it happen? Make your response very short.
The helium-filled balloon rises upward when Emeka lets go of the string. Helium is less dense than the surrounding air; therefore, it experiences a buoyant force which is an upward force that fluids exert on objects in them. This buoyant force is greater than the weight of the balloon, causing it to ascend into the sky.