An English archery club a few years ago posted a study of the physics of the longbows that the English used to defeat a much larger French army at Agincourt in 1415. It’s a detailed analysis of trajectories, kinetic energies, and bow designs. Don’t bother with the math (unless you’re into that sort of thing). Jump to the conclusion, summarized in the last paragraph:
It is sobering to combine these facts with some historical data. Henry had approximately 5,000 archers at Agincourt, and a stock of about 400,000 arrows. Each archer could shoot about ten arrows a minute, so the army only had enough ammunition for about eight minutes of shooting at maximum fire power. However, this fire power would have been devastating. Fifty thousand arrows a minute – over 800 a second – would have hissed down on the French cavalry, killing hundreds of men a minute and wounding many more. The function of a company of medieval archers seems to have been equivalent to that of a machine-gunner, so in modern terms we can imagine Agincourt as a battle between old-fashioned cavalry, supported by a few snipers (crossbow-men) on the French side, against a much smaller army equipped with machine guns.
Agincourt, by the way, was the inspiration for Shakespeare’s Henry V.