Introduction Friction is an important force that affects us every day. It’s the force that allows us to walk or ride a bicycle—without friction, we’d slip and slide all over the place. Friction is what helps everything from car brakes to a baseball as it is thrown. In this lesson, we’ll learn more about the basics of friction and explore some fun experiments that allow us to experience this force first-hand.

What is Friction? Friction is the force that happens when objects rub against one another. It can be a helpful force, like when you use a pencil to write on paper, or a hindering force, like when you try to skid across a carpet.

Types of Friction There are two main types of friction: sliding friction and static friction. Sliding friction occurs when two surfaces with different textures move against one another. An example of this would be when you rub your hand against a sandpaper-like surface. Static friction occurs when two surfaces are not moving, but one is trying to move against the other. An example of this would be when you try to push a heavy drawer—the more you push, the harder it is to get started.

Experiment: Used to Show Sliding Friction Materials: -ruler -two pieces of paper with different textures -tape

Instructions: 1. Place the ruler flat on a surface and tape the two pieces of paper to each end of the ruler. 2. Place an object such as a book or a coin on the center of the ruler. 3. Apply pressure on the book or coin, and slowly pull the pieces of paper apart. 4. Observe how far the book or coin slides before the paper tears or the ruler slides.

Result: The book or coin should be able to move further on the paper with less texture when compared to the paper with more texture. This experiment can help demonstrate how the type of surface affects sliding friction.

Experiment: Used to Show Static Friction Materials: -ruler -two pieces of paper with different textures -tape -object that is light enough to be pushed (such as a beanbag or a ball)

Instructions: 1. Place the ruler flat on the surface and tape the two pieces of paper to each end of the ruler. 2. Place the object in the center of the ruler. 3. Push the object in one direction and observe how much force it takes to move the object. 4. Switch the papers and repeat the experiment.

Result: The object should take more force to move on the paper with more texture than the paper with less texture. This experiment can help demonstrate how the type of surface affects static friction.

Conclusion: Friction is a force that affects us every day, and it can be both helpful and hindering. Through the experiments we have done, we have seen that the type of surface can have an effect on the force of friction. Understanding friction can help us to use it for our benefit, such as building better brake systems for cars or better shelves for the objects we keep.