# Balloons Paper

Why does a hot air balloon float even though it is so heavy?

Hot air balloons float because the buoyancy force of the hot air is more than the weight. Buoyancy occurs because the hot air has a lower density than the cooler outside air. This lower density air weighs less than the air it replaces and that difference is the buoyancy.

What makes balloons float when they are full of air but not float when they are deflated?

Balloons float when they are full of hot air because the hot air weighs less than the air that is in the chamber which results in a floating balloon.

Starting with a hot air balloon, figure out how to make the balloon float. What factors affect the balloon floating or sinking? Explain three of these factors and your understanding of why this works as it does.

When the air is heated in the balloon, it cause the balloon to rise. This is because hot air is less dense than warm.

Over time, if no more hot air is pumped into the balloon, the air cools and so the balloon falls.

Move to the rigid hollow sphere. What does it mean that the sphere is “rigid?”

A rigid sphere refers to a sphere that possesses an impenetrable shell

5. Play with the parameters of the simulation and get the sphere to float. How is the sphere floating similar to and different from the floating hot air balloon?

The sphere is similar to the hot air balloon in its bobbing motion when nothing is added to the system.

However, when species are added to the inside of the sphere, the result ends with a sinking sphere. This is much different than the hot air balloon when a gas species was added to the inside of the balloon which resulted in more a floating action in the balloon. They both behave similarly when exposed to different species as they are added to the chamber. The species bounce off of both the balloon and sphere which alter their path. They both react the same to heat and cold. Both sink with cold temperatures and float more with hotter temps.

How will you get the helium balloon to float? Explain how you plan to set all the parameters to get the balloon floating.

By understanding that when balloons float they have helium in it. Helium is not air, but a gas. It’s lighter than air, which makes it float. So, hopefully by adding helium to the balloon and making the air heavier, the balloon will rise.

7. Set the parameters as you predicted above. Did it work? If so explain why this worked. If not explain why your predictions didn’t work and what you did to change it.

To get the helium balloon to float, one must add helium atoms to the ballon, pump a small amount of heavy species into the chamber and increase the pressure exerted on the chamber. The result is that the helium weighs less then the surroundings which results in the balloon floating.

Summarize your findings, how does a hot air balloon that is so heavy float in air?

The air particles in hot air are much further apart, making the air less dense. The colder surrounding air’s particles are much closer, making them more dense. The lighter hot air rises above the denser cold air, thus the hot air balloon is airborne.