Teach students that an object at rest will resist an outside force. Place a flat piece of paper underneath a hardcover book with a glossy cover. Have students pull the paper out from underneath the book as quickly as possible. Notice that the book does not move at all. Place the paper back underneath the book and then place objects on top of the book. Again, quickly pull the paper out from underneath the book. Notice that the book and the objects on top still move very little. Next take the glossy cover off of the book and again place the paper underneath. Now there is more friction between the paper and the book. Again, students should place objects on top of the book and quickly remove the paper. This time the objects and the book move more because of the added friction. Students learn about inertia, friction and Sir Isaac Newton's First Law of Motion.
In this activity, students are asked to determine whether an egg is raw or hard-boiled depending upon how the egg spins. Give students an egg and have them spin it on their desk or another smooth surface. The hard-boiled egg will spin smoothly and consistently. However, the raw egg will wobble and spin inconsistently. At first, the liquid inside the raw egg is still. As the egg is spun, the liquid inside is resistant to movement and therefore sloshes against the shell, thus throwing the egg off balance. Students should observe each other's eggs and determine which are raw and which are hard-boiled.
Gather a group of the same coins and stack them on top of one another, at least four or five inches high. Leave one coin remaining and shoot and slide this coin toward the bottom coin of the stack. The bottom coin should quickly shoot out from the stack, while the stack remains intact. Students should repeat this until there are no coins remaining. The inertia of the stack of coins is so great that the force from a single coin cannot move the entire stack. The moving coin has just enough inertia to move the single coin on the bottom.
This activity requires an unsharpened pencil and a long narrow strip of paper. Lay the strip of paper down on a flat surface such as a desk and place the unsharpened pencil upright on top of the paper. Instruct the students to try and pull the paper out from underneath the pencil without its falling down. The pencil will repeatedly fall down. Next place the paper onto the desk so that it partially hangs off the edge of the desk. Place the unsharpened pencil upright on the paper. This time, instruct the students to pull the paper out from underneath the pencil by pulling on the portion of paper hanging down from the desk. The paper should move so fast that the pencil remains standing. In this activity, the pencil wants to resist the force of the moving paper. When the paper is moved quickly, the pencil resists the force and stays upright. However, when the paper is moved slowly, the movement affects the pencil and forces it to fall down.