Introduction

Diagram Description:

• all measurements are in "units of your choice"
• center of mirror marked with red dot
• center of target marked with red dot
• laser is shown by half red circle
• mirror is 10 units long
• target is 10 units long
• mirror does not move; it rotates around its center
• target does not move or rotate
• laser can be pointed in any direction inside the box
• laser can reflect off any part of the mirror
• target is flush with the box wall

Use the law of reflection: the angle of incidence equals the angle of reflection.

Project #1

Create a program that:

• allow the user rotate the mirror around its center
• allow the user to aim the laser in any direction inside the box (+90° straight-up to -90° straight-down)
• allow the user to fire the laser
• if the user missed the target, display a "missed" error message, including where it hit and by how much.
• loop

Display a menu and let the user select the actions. (A GUI or graphics can come later.)

Should you make it a game?

What does the user wins if they hit any part of the target? Perhaps 5 point for hitting the center of the mirror and 1 point for hitting the end. Anywhere between the center and the end is scaled between 1 to 5? Perhaps limit the user to five tries at hitting the mirror?

Coordinate System

Should you use Cartesian coordinates with the origin (0,0) the center of the box?

If a Graphics Program?

Use graphics.py. Click HERE for more information. (download, install, documentation, etc.)

Project #2

Add a second mirror. The user must aim the laser to reflect off of both mirrors before hitting the target.

Project #3

Try This

a. Add a GUI.
b. Add a second, third, forth, ... mirror.
c. Assume there is no mirror but the box walls are mirrors. Aim the laser to reflect off of two walls to hit the center of the target.
d. Try three walls, ...

Math Stuff

What is Sine and Cosine

Law of Sines

 sin(α)     sin(β)     sin(δ)
-------- = -------- = --------
   A          B          C

Use the Law of Sines to solve oblique triangles. Any triangle that is not a right triangle is an oblique triangle.

The Start of a Solution

Lets analyze the problem and break it into manageable parts.