My PBL Project

INTRODUCTION:

This project attempts to explain the physics of roller coasters, specifically the loop-the-loop, with the formulas of uniform circular motion. The roller coaster used in this demonstration is built with Kinex supplied by the Harmony School of Innovation, though Kinex are definitely not the only way to go in this project

Driving Question: How does the roller coaster car make a sharp turn or loop upside-down without falling?

MATERIALS:

• Model roller coaster with a loop-the-loop feature (Kinex in this case)

• Coaster cars

• Small cup of water

• Camera

PROCEDURE:

1. Construct the roller coaster and make sure that it runs smoothly

2. Fill the small cup with water

3. Place cup of water on the roller coaster cart

4. With the camera rolling, release the cart down the hill

5. Observe

SCIENTIFIC PRINCIPLE:

The physics of uniform circular motion play an important role in the success of the roller coaster. When the cart is at the top of the hill, it has a large amount

of potential energy. As it begins to travel down the hill, it transforms this potential energy into kinetic energy and momentum. This kinetic energy is key. Upon entering

the loop, the cart begins to experience centripetal force due to the circular nature of the aforementioned loop. This centripetal force, combined with the inertia of the

cart, is responsible for what is known as "centrifugal force". Centrifugal force is not a real force, but rather a combination of inertia and centripetal force.

To explain this phenomena from a different perspective, consider the experience of riding a real roller coaster. When the cart approaches the loop, it is traveling with

considerable momentum and velocity horizontally. However, the loop is not horizontal. When the cart starts travelling vertically, its horizontal momentum presses it into

the rail because, as a result of inertia, it resists change in motion. This disparity between inertia and direction of travel persists until the car exits the loop and continues

on its way.

SAFETY REGULATIONS:

There were no necessary safety precautions that need to be taken before beginning this project.

IMAGES OF THE PROJECT:

The roller coaster was built in sections. These sections were attached as they were built to create the final product.

The chain and rails before being installed.

Photo credits to Noah Simpson