Question

Hollywood often portrays bows as extremely lethal. In reality, however, they were being replaced by firearms on the battlefields of Europe already towards the end of the 100 years’ war (1337-1453). While all early projectile weapons were very inaccurate (sights are a recent invention), the most striking difference between the bow and the musket lies in the kinetic energy carried by the projectile. A well trained archer using the famous British Longbow could fire an arrow of about 100 grams (0.1 kg) with an initial energy of approximately 100 J.

QUESTION 1: Compare this to a black-powder musket and a modern rifle. Flintlock muskets typically fired a 30 gram projectile with an initial velocity of 200-300 m/s, whereas a modern US M4 carbine fires a 4 gram bullet at 910 m/s.

QUESTION 2: What would the recoil momentum be for all three weapons?

QUESTION 3: If we assume that the longbow stores energy like a spring, what would the spring constant k be? For simplicity, assume that the displacement is equal to the length of the arrow, which was about 30 inches (0.76 m).

QUESTION 4: In movies and works of fiction skilled archers are sometimes portrayed releasing multiple arrows at the same time. A real archer would, however, never do this. Why?

Answer 1