[quote=@Vordak]
Innue, here's a question for you: can i have a weapon achieve supersonic speeds if it's a 2.5 meter long whip with a steel arrowhead tip and 70 cm long handle? It also would be quite stiff, able to harden upon impact and leave deep cuts in flesh or even slice through leather armor, as far as i have planned.
[/quote]

Not sure how familiar you are with whips... 

You need to understand in most practical motions, the whip will not achieve that speed on the tip unless you are trying to intentionally crack it, which is different than trying to strike something intentionally with the tip.