Fair Warning: Omnicalculator's Relativistic KE Calc is Wrong

[Flashlight237]

So, a lot of our calcs use Omnicalculator's Relativistic KE calculator and... Well, I come to find out that the way that calculator handled relativistic KE is actually wrong. So I did the math with fixed values: 0.95c for speed and 1 kg for mass. So when plugging in the values for relativistic KE on Omnicalculator's KE, the value came out as this: https://prnt.sc/fsCb07KGNqQB

Yep. That's 197956497114093661 joules. Problem is, when I actually use the relativistic KE formula, I got the following:

γ=1/(√(1-v²/c²))
γ=1/(√(1-.95))
γ=1/0.2236067977=4.472135955

(4.472135955-1)*1*299792458²=3.120600171*10^17 joules

I tested it again, this time using 0.5c instead of 0.95c and... Well, here's what I got from Omnicalc (1.3*10^16 joules): https://prnt.sc/jr4F6olI02RK

And here's what I got using the relativistic KE formula proper:

γ=1/(√(1-v²/c²))
γ=1/(√(1-.5))
γ=1/0.7071067812=1.414213562

(4.472135955-1)*1*299792458²=3.722765843*10^16 joules

I had my suspicions when I used Omnicalculator's relativistic KE formula and repeatedly got negative values, but yeah, it turns out Omnicalculator's Relativistic KE calculator is just wrong. So yeah, here's my fair warning: don't use Omnicalculator's KE. You wouldn't believe how off you'll be.

Update: I double-checked my math and I'm wrong. Whoops.