Unfortunately, yet just another story like this. One of these unexpected usage charges in the thousands appears every month, and with the same automatic denied too. This is one of the reasons I just stopped using these kinds of pay-per-usage cloud services long ago. At best, I still use services that have hard-bounded usage limits, like EC2 from AWS, where one instance can never go beyond 24h/day usage and is always capped, with shutdowns when exceeded, and limited credit cards, too.

It's super frustrating that this is the only option to realistically deal with this issue, since all stories end up the same way: The cloud company just saying "f* you, we don't care, pay up." and legal fees are always expensive :(

> At best, I still use services that have hard-bounded usage limits, like EC2 from AWS, where one instance can never go beyond 24h/day usage and is always capped, with shutdowns when exceeded, and limited credit cards, too.

Is this possible on AWS today? I'm the same way, if I cannot set a hard-limit for the billing so I can know for a fact how much it'll maximum cost in a month, I'm not interested in using that service for anything. Which is one of the top reasons I've stayed clear of AWS, they used to have only billing-alerts, but you couldn't actually set limits, guess one step forward that they've finally implemented that now.

In reality, nothing is perfect. Materials are never 100% one material. Rustness is imperfection, the weight and material of the ball, and the place it's attached are also consideration points, how firmly it is attached, and with which material. A "perfect" simulation of the spring itself would have to consider all these variables, and they almost never do.

And even if you somehow included "everything" with the "perfect" equations, you'll end up with a lot of stuff which does not have a good closed form solution anyways and good luck getting that running (e.g. the dynamics around the air resistance/sound generation) via approximations both accurate enough that it looks better than "faking it" and fast enough that it's actually usable interactively.

This leads to what GP was saying: many just cut things off at "Hooke's law simulates a spring, so I'll use that, but the rest is a bit too much to fit so I won't do it" but "Hooke's law simulates a spring but adding a bit of not-physics based fluff approximates all the rest" actually gives far superior results even though it doesn't only use perfect physics equations as the former did.