We have all been amused by the behavior of an inflated balloon when left loose without tying its mouth. This dynamic action has some principles behind it and Isaac Newton, an English scientist, explained why this happens centuries ago. He said that for every action there is a reaction with equal force in the opposite direction. This Newton’s law became known as his Third Law of Motion and may or may not be found in homeschooling programs such as the Apology science curriculum. However, I love bringing this principle to life in your homes by teaching you some cool rocket experiments.
When we blow air into a balloon, we apply a force to the rubber wall of the balloon. This wall exerts an equal force backwards. Therefore, as soon as we release the mouth of the balloon, the wall pushes the air out. Now, as the air is forced out of the balloon, an equal force works in the opposite direction and pushes the balloon in the opposite direction. This is the same principle that is used to launch rockets.
A rocket engine burns fuel, and therefore a large amount of gases are released. The jet of gases hits the ground with great downward force. Now, according to Newton’s third law, an equal force acts on the rocket in the opposite direction (up). Thus, a large thrust is created and the rocket is launched into the sky. You may have read about this in the Apology science curriculum or elsewhere, but I will teach you how to have fun making this happen in your home.
Seltzer Squeeze Rocket: Fill an empty (preferably clear) film roll canister one-third full with water. Place an effervescent tablet (such as Alka-Seltzer) in it. Put the lid on and quickly invert the canister onto a sidewalk. What happens? The boat is launched into the air in the same way that a rocket is launched.
When the effervescent tablet reacts with water, it releases carbon dioxide gas. This gas collects in the container and ultimately triggers a mini-explosion. The gas applies a downward force on the lid. As a result, an equal force acts on the boat in the opposite direction, launching it. Repeat with two tablets and see what happens.
Take the help of adults while doing this experiment. Also wear protective glasses. What does this experiment tell you about the amount of fuel it takes to launch a rocket? What do you learn about the amount of force required to generate the equal and opposite launch force of the rocket? To get a better idea, watch a video of a real life rocket launch.
If you have been looking for programs like the Apologia science curriculum or others, you need look no further. You will find my experiments very easy to perform, and the best thing is that the materials you will need can be found around the house. Take a look at another exciting experiment.
Paper Tube Rocket: Make a paper tube by winding a spiral strip of paper around a pencil. Tape the tube down in a few places and slide the pencil through. Bend the top end of the tube so that air does not pass through it, and tape it down to form the nose. Now insert a drinking straw into this tube rocket and blow hard to launch your rocket.
Want some more exciting ideas? Download your free “Homeschool Parent’s Guide to Teaching Science” full of great science experiments and activities at the link below.