| If you have ever noticed a bird flying, you will see how | | | | experiment. If you've ever been in a hot air balloon, you |
| it uses its inherent ability to rightly use the aerodynamic | | | | will notice that the pilot adjusts the burner in order to |
| forces to fly high in the sky as well as glide through the | | | | make the balloon go upwards and downwards. He |
| clouds tirelessly and effortlessly. I use these principles in | | | | also uses the winds, caused by a difference in air |
| a myriad of exciting homeschool science experiments, | | | | pressure, to move from place to place. Let's make our |
| some of which I will share below. | | | | own hot air balloon using a garbage bag. |
| These 4 aerodynamic forces are thrust (the force that | | | | Hot Air Balloon Experiment: Open up a garbage bag |
| makes a bird move forward), drag (the force of | | | | and make the mouth very narrow using duct tape. |
| resistance which the bird has to minimize), lift (the force | | | | Make sure to leave a small hole to fill-in hot air. Now |
| that makes the bird rise high) and gravity (the force | | | | run a hair dryer for a few seconds till it blows hot air |
| that pulls the bird down). A slight imbalance in the | | | | and then fill the bag with hot air. Now switch off the |
| above- and the flight would not be as graceful. | | | | hair dryer and let go of the bag. The bag begins to rise |
| It is important to note that the force of lift and thrust is | | | | towards the ceiling, where it stays for some time. |
| generated when the birds flap their wings. They also | | | | Hot air has less density. This means that there are |
| create a lift while gliding against a current of wind by | | | | fewer air particles inside the hot air balloon as |
| tilting the front edges of the wings to create a | | | | compared to the outside atmosphere. Therefore there |
| difference in air pressure. Drag is minimized by the | | | | is less air pressure inside the hot air balloon as |
| aerodynamic shape of the bird's body. Also, birds have | | | | compared to the outside air. This makes the balloon |
| hollow bones, making them lighter and reducing the | | | | rise. |
| effects of gravity. I will share some of my favorite | | | | Tissue Parachutes: Take four pieces of thin strings or |
| homeschool science experiments below to | | | | sewing thread of equal lengths. Tie the threads to the |
| demonstrate how objects rise in the air and why flying | | | | four corners of a tissue paper. Tie the free ends of |
| objects must be light in weight. | | | | the four strings to a piece of stick. Prepare many such |
| Airplanes and rockets are designed with these | | | | parachutes with different weights attached. Now drop |
| principles in mind. One or more of the above | | | | them one by one from a balcony. Notice how fast |
| mentioned forces are dominant depending on the | | | | each one drops to the ground. |
| function of the flying object. Even if you and I had | | | | Do you now realize why it is important for birds and |
| wings, we wouldn't be able to fly since our bodies are | | | | airplanes to be light in weight? |
| not aerodynamically shaped and we are heavy. | | | | The free "Homeschool Parent's Guide to Teaching |
| Now that you have learned something about | | | | Science" is filled with great science experiments and |
| aerodynamics, let's have fun with a hot air balloon | | | | activities. Get your copy by clicking the link below. |