 My name is Saw and I'm a Yale 2020 intern at the San Francisco Public Library. Today you'll be making your own cardboard maze. If you want a challenge, try to create a maze that can keep the ball rolling as long as possible. Let's get started. First, we are going to talk about the engineering design process which can really help you start designing your maze. The first step is to identify the challenge and the limits. Do some research if you need more information. Next, brainstorm a few ideas for your maze. Draw some sketches of your design and choose one that you think will work best. Then, build a model based on your design and test your prototype several times. Keep track of the data like the test runs and take notes. Afterwards, observe and look forward to improve on. Modify your design and prototype if you need to. Finally, choose the best design. In this case, it will be one that can keep the ball rolling the longest and one that works. Now, let's look at an example of the cardboard maze. This is an image of the full cardboard maze. Now, let's talk about some science concepts behind the maze. Friction is the force that slows objects down when they are rubbing against each other. In the image, there is friction when the ball is rolling because it is rubbing against the ground. When you are building your maze, you want the ball to have a little friction so that it rolls longer. Some examples of friction are breaks on a tire and skates on ice. Gravity is a force that pulls objects down towards the center of the earth. In the image, gravity causes the apple to fall towards the ground. Similarly, gravity is also pulling the ball down the ramp. The ball is already rolling fast since it is going downhill. But as gravity pulls on it, the ball has an even faster speed. Momentum is how much motion an object has. It is also known as a mass in motion. This is because an object has a mass and if that object is moving, it has a mass in motion. Therefore, a moving object has momentum. For example, the ball has momentum when it rolls down the maze. When you are building your maze, you want the ball to not lose its momentum. If the ball loses momentum, it will stop rolling. Speed is the measure of how fast an object moves. For example, the speed of the car is that it is traveling at 40 miles per hour. When you are building your maze, you can lower the speed of the ball if you want it to roll longer. The law of inertia states that an object at rest will stay at rest and an object in motion will stay in motion with the same speed and in the same direction unless there is a force on the object. In other words, if an object has inertia, it wants to keep doing what it is already doing unless a force like gravity or friction stops it. In the image, the ball at rest will stay at rest unless there is a force on the ball. The ball in motion will stay in motion unless a force stops the ball. Potential energy is the energy that is stored in an object due to its position. An object that is staying still has potential energy. In the image, the ball has potential energy since it is not moving at all. Kinetic energy is the energy of an object that is in motion. In the image, the ball has kinetic energy as it rolls down the slope. Now is your turn to build your own cardboard maze. The following steps will guide you through the building process. First, bring down a few ideas and come up with your own design. As you are drawing the sketches, think of the questions below. What will cause the ball to speed up as it goes along? And what will cause it to slow down? Next, find the materials you might need. It will be great if you can use recycled materials found at your home. Basic materials include a timer or stopwatch, a pair of scissors, duct tape or masking tape, a big piece of cardboard, a ball of your choice, it could be a marble, a rubber ball or ping pong ball, and some paper towel tubes and cardboard pieces to build the tracks on the maze. Once you have the materials ready, start building a maze based on your own design. Then test your prototype several times to see if it works or not. Next, use a timer or stopwatch to see how long the ball rolls and record the data of your test runs. Afterwards, observe your maze as the ball runs. Then think of what you should do to improve your maze or think of what should be kept the same on the maze. Redesign if you need to. The last part is the reflection. After you finished building your maze, think of the following questions. What structures make the ball roll faster? What structures or surfaces are best for slowing down the ball? How did the length and direction of your tubes help to slow the ball down? Is it easier to design a maze that slows the ball down or designing one that makes it go fast? Be sure to check out the rest of the STEM Challenge yourself videos by SFPO librarians and your interns.