E-CodeGravitation: force, orbits, escape speed — a TI-84 Plus CE program
GRAVITY is a TI-BASIC program for the TI-84 Plus CE. Gravitational force between two masses, surface gravity of a planet, or a circular orbit at any altitude: orbital speed, period (in s and hours) and the escape speed from that height. G = 6.6743ᴇ-11; distances are centre to centre, altitude is above the surface.
What it asks for and what it shows
It asks for 3 values at its prompts, after you pick option 1 from its menu. In the example below it shows F (N).
Example run
One of its oracle test cases: “Earth and Moon”. The inputs are typed in order, and the results are the values the case expects on the screen.
| Step | Value |
|---|---|
| You enter | |
| Menu | option 1 |
| Input 1 | 5.972ᴇ24 |
| Input 2 | 7.348ᴇ22 |
| Input 3 | 384400000 |
| The screen shows | |
F (N)= | 1.982110729E20 |
How it's checked
5 test cases, each checked against an independent method. Replayed key by key on a virtual TI-84 Plus CE, they make 19 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 “Gravitation: force, orbits, escape speed” (GRAVITY).
- 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