E-CodeRefraction: Snell's law and total internal reflection — a TI-84 Plus CE program
SNELL is a TI-BASIC program for the TI-84 Plus CE. Light going from index n1 into n2 at an angle (measured from the normal): the refracted angle, or TOTAL INTERNAL REFLECTION when it can't get out, the critical angle when n1 > n2, and the speed of light in the second medium.
What it asks for and what it shows
It asks for 3 values at its prompts. In the example below it shows OUT DEG, V2 M/S.
Example run
One of its oracle test cases: “air into water at 30 degrees”. The inputs are typed in order, and the results are the values the case expects on the screen.
| Step | Value |
|---|---|
| You enter | |
| Input 1 | 1 |
| Input 2 | 1.333 |
| Input 3 | 30 |
| The screen shows | |
OUT DEG= | 22.03010873 |
V2 M/S= | 224900568.6 |
How it's checked
4 test cases, each checked against an independent method. Replayed key by key on a virtual TI-84 Plus CE, they make 18 checks.
How E-Code checks every program
Run it or put it on your calculator
- Open the library in the TI-84 Plus CE calculator and pick “Refraction: Snell's law and total internal reflection” (SNELL).
- Put it on your own calculator with a computer and a USB cable, or type it in by hand.
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All TI-84 Plus CE physics programs · All TI-84 Plus CE programs