Third Grade Physics – Supercharged Science

Getting Started

We’re going to study velocity, acceleration, forces, and Newton’s three laws of motion in this section. You’ll get to throw things, build g-force accelerometers, and much more as you uncover the basis of all physics in our crash-course in projectile motion. Newton has a famous quote that goes “If I have seen farther then others, it is because I have stood on the shoulders of giants.” One of the giants he was referring to was Galileo. Thanks to the discoveries of Galileo and others, Newton was able to make many of his own discoveries. The most famous of which are Newton’s Laws of Motion.

Newton’s Laws are all they used to get the first man to the moon. They are an amazingly powerful and wonderful area of physics. I like them because evidence of them is everywhere. If something moves or can be moved, it follows Newton’s Laws. You can’t sit in a car, walk down the road, drink a glass of milk, or kick a ball without using Newton’s Laws. I also like them because they are relatively easy to understand and yet open up worlds of answers and questions. They are truly a foundation for understanding the world around you.

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	Driveway Races This experiment is one of my favorites in this acceleration series, because it clearly shows you what acceleration looks like. The materials you need is are:
	Downhill Race Newton’s Second Law is one of the toughest of the laws to understand but it is very powerful. In its mathematical form, it is so simple, it’s elegant.
	Force-full Cereal Did you know that your cereal may be magnetic? Depending on the brand of cereal you enjoy in the morning, you’ll be able to see the magnetic effects right in your bowl. You don’t have to eat this experiment when you’re done, but you may if you want to (this is one of the ONLY … Continue reading "Force-full Cereal"
	Flying Paper Clip Have you ever been close to something that smells bad? Have you noticed that the farther you get from that something, the less it smells, and the closer you get, the more it smells? Well forces sort of work in the same way. Forces behave according to a fancy law called the inverse-square law. To … Continue reading "Flying Paper Clip"
	Detecting the Magnetic Field Remember, there are four different kinds of forces: strong nuclear force, electromagnetism, weak nuclear force, and gravity. There are also four basic force fields that you come into contact with all the time. They are the gravitational field, the electric field, the magnetic field, and the electromagnetic field. Notice that those four force fields really … Continue reading "Detecting the Magnetic Field"
	Rocket Ball Launcher This is a satisfyingly simple activity with surprising results. Take a tennis ball and place it on top of a basketball… then release both at the same time. Instant ball launcher! You’ll find the top ball rockets off skyward while the lower ball hit the floor flat (without bouncing much, if at all). Now why … Continue reading "Rocket Ball Launcher"
	Forever Falling If I toss a ball horizontally at the exact same instant that I drop another one from my other hand, which one reaches the ground first? For this experiment, you need:
	A Weighty Issue This lesson may give you a sinking sensation but don’t worry about it. It’s only because we’re talking about gravity. You can’t go anywhere without gravity. Even though we deal with gravity on a constant basis, there are several misconceptions about it. Let’s get to an experiment right away and I’ll show you what I … Continue reading "A Weighty Issue"
	Building Bridges What keeps building from toppling over in the wind? Why are some earthquake-proof and others not? We’re going to look at how engineers design buildings and bridges while making our own. Here’s what you need:
	Barrel Roof This roof can support over 400 times its own weight, and you don’t need tape! One of the great things about net forces is that although the objects can be under tremendous force, nothing moves! For every push, there’s an equal and opposite pull (or set of pulls) that cancel each other out. This barrel … Continue reading "Barrel Roof"
	Newton’s Third Law of Motion Third Law of Motion: For every action, there is an equal and opposite reaction. Force is a push or a pull, like pulling a wagon or pushing a car. Gravity is a force that attracts things to one another. Weight is a measure of how much gravity is pulling on an object. Gravity accelerates all … Continue reading "Newton’s Third Law of Motion"
	Newton’s Second Law of Motion Second Law of Motion: Momentum is conserved. Momentum can be defined as mass in motion. Something must be moving to have momentum. Momentum is how hard it is to get something to stop or to change directions. A moving train has a whole lot of momentum. A moving ping pong ball does not. You can … Continue reading "Newton’s Second Law of Motion"
	Newton’s First Law of Motion First Law of Motion: Objects in motion tend to stay in motion unless acted upon by an external force. Force is a push or a pull, like pulling a wagon or pushing a car. Gravity is a force that attracts things to one another. Gravity accelerates all things equally. Which means all things speed up … Continue reading "Newton’s First Law of Motion"
	Detecting the Electric Field You are actually fairly familiar with electric fields too, but you may not know it. Have you ever rubbed your feet against the floor and then shocked your brother or sister? Have you ever zipped down a plastic slide and noticed that your hair is sticking straight up when you get to the bottom? Both … Continue reading "Detecting the Electric Field"
	Look Out Below! If you jump out of an airplane, how fast would you fall? What’s the greatest speed you would reach? Let’s practice figuring it out without jumping out of a plane. This experiment will help you get the concept of velocity by allowing you to measure the rate of fall of several objects. It’s also a … Continue reading "Look Out Below!"
	Balloon Racers We’re going to experiment with Newton’s Third law by blowing up balloons and letting them rocket, race, and zoom all over the place. When you first blow up a balloon, you’re pressurizing the inside of the balloon by adding more air (from your lungs) into the balloon. Because the balloon is made of stretchy rubber … Continue reading "Balloon Racers"
	Special Science Teleclass: Rocketry & Spaceflight This is a recording of a recent live teleclass I did with thousands of kids from all over the world. I’ve included it here so you can participate and learn, too! Blast your imagination with this super-popular class on rocketry! Kids learn about fin design, hybrid and solid-state rocketry, and how rockets make it into … Continue reading "Special Science Teleclass: Rocketry & Spaceflight"
	Special Science Teleclass: Physics of Motion This is a recording of a recent live teleclass I did with thousands of kids from all over the world. I’ve included it here so you can participate and learn, too! We’re going to cover energy and motion by building roller coasters and catapults! Kids build a working catapult while they learn about the physics … Continue reading "Special Science Teleclass: Physics of Motion"

Getting Started

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