[bkanber]

You're totally correct. And honestly, when you're doing numerical simulation like I am in the article, your error stems from the fact that you're only simulating 40 steps a second with only a first-degree solver.

Simulating physics for realsies takes a lot more than that.

The solver algorithm I used is called Euler's method, or ODE1 for short. It's the least accurate numerical ODE solver there is! When people do real physics simulations they use the Runge-Kutta (ODE45) or Adams-Bashforth-Moutlon (ODE113) solves, and they'll have 100,000 steps per second.

So while it's important to be cognizant of these things, it's also best not to stress to much about what's going on in the first of a series of educational articles :)