Alpha is often used in physics and chemistry as a symbol or in the names of things, for example alpha particles (which are two protons and two neutrons bound together into a particle the same as a helium nucleus). The symbol is also used a lot in mathematics in algebra, for example naming angles.
Recurve bow. A recurve bow is a bow with limbs that curve away from the archer when unstrung. A recurve bow stores more energy and delivers energy more efficiently than the equivalent straight-limbed bow, giving a greater amount of energy and speed to the arrow.
Traditional target arrow (top) and replica medieval arrow. Modern arrow with plastic fletchings and nock. An arrow is a fin-stabilized projectile that is shot with a bow, and usually consists of a long straight shaft with a weighty and usually pointed arrowhead attached to the front end, with fletchings and a nock at the rear end. The use of bows and arrows by humans predates recorded history and is common to most cultures.