Lab Files

### Lab 5: Projectile Motion and Air Density

#### Introduction

In today's lab we will launch our rocket at an angle relative to the horizontal, with and without air resistance.  We want to compare the range and maximum height achieved by the rocket for various input values.

You will be working a with new base code in today's lab. Here are the changes:

• The rocket's motion is modeled using the Velocity Verlet algorithm.  This is a very simple and fast algorithm that provides enough accuracy for our purposes.
• We are using a slightly different air-resistance model, one in which the resistive force is based on the square of the rocket's speed.  The drag coefficient will have a different value (~3.8).
• The user is prompted for the launch angle (relative to the horizontal)  and time step.
• The rocket rotates to follow its velocity vector.
• A trajectory line traces the rocket's path.
• To accommodate the longer trajectory, the scene has been rescaled.

#### Learning Goals

At the end of this lab you should have a good conceptual understanding of how we model air resistance in a numerical simulation. You should also find that your programming skills are improving, and that it takes you less time to do the same kinds of things you've been doing since the first lab.

#### What To Turn In

• For Exercise 1: Modified code and Excel spreadsheet.
• For Exercise 2: Modified code and Excel spreadsheet.