E-CodeTerminal settling velocity of a sphere — a TI-84 Plus CE program
TERMVEL is a TI-BASIC program for the TI-84 Plus CE. Sphere falling through a fluid with the Schiller-Naumann drag law, solved by bisection: terminal speed, Reynolds number, drag coefficient, and the Stokes-law error.
What it asks for and what it shows
It asks for 4 values at its prompts. In the example below it shows VT M/S, RE, CD, VSTOKE, ERR %.
Example run
One of its oracle test cases: “fine sand in water (Stokes regime)”. The inputs are typed in order, and the results are the values the case expects on the screen.
| Step | Value |
|---|---|
| You enter | |
| Input 1 | 0.1 |
| Input 2 | 2650 |
| Input 3 | 998 |
| Input 4 | 1 |
| The screen shows | |
VT M/S= | 0.007979753149 |
RE= | 0.7963793643 |
CD= | 34.00230292 |
VSTOKE= | 0.0090034 |
ERR %= | 12.82805159 |
How it's checked
6 test cases, each checked against an independent method. Replayed key by key on a virtual TI-84 Plus CE, they make 38 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 “Terminal settling velocity of a sphere” (TERMVEL).
- Put it on your own calculator with a computer and a USB cable, or type it in by hand.
Related programs
- Pipe friction: Colebrook, Darcy-Weisbach
- Flat-plate boundary layer and drag
- Pipe network: series + parallel
- Venturi meter and Pitot tube
- Open channel: Manning, critical depth
All TI-84 Plus CE engineering programs · All TI-84 Plus CE programs