Remember playing cowboys and Indians as a kid, running around with cap guns, bows and arrows, and those infamous stick horses? Well back when we were kids, we probably didn’t know that gravity was affecting each one of our arrows. Now, older and wiser, we understand how gravity works, but do we really understand how gravity affects the trajectory of an arrow?
To begin with, imagine shooting a bow and arrow. When drawing back the bowstring you are creating tension that will provide kinetic energy for your arrow. The second the arrow leaves the bow, that energy is displayed through the arrow’s flexing, vibration, and speed. All these effects impact its flight pattern. In addition, gravity instantly begins to play a role. While losing kinetic energy the arrow is heading towards the ground at a descending rate of 9.8 meters per second squared (9.8 m/sec^2) or 32.2 feet per second squared (32.2 ft./sec^2.) Note: not accounting air resistance. Air resistance is the frictional force air applies against a moving object. In this case, an arrow. As an arrow moves, air resistance slows it down. The faster the arrow's movement, the greater the air resistance exerted against it.
Now, let’s break it down even further. It’s all in the name “ARCH-ery.” Just like the name states, an arrow has a path that creates an arch. If you are shooting towards a horizontally placed target the arrow will actually fly in an upward manner and then arch downward until it hits the target or the ground. Thus, the arrow crosses your line of sight twice. The sights on our PSE Viper SS crossbow allows you to compensate for arrow drop just by the turn of a knob.
The graph below shows how many inches a horizontally shot arrow has descended over longer lengths. This test shows results with the arrows provided with the Alpha Outpost Artemis box. These test results will vary if using different size and weighted arrows.
By looking at the data you can see that gravity is constantly there. Again, this graph shows a particular arch because its overall characteristics and setup (arrow length, arrow weight, crossbow draw, etc.) We encourage everyone to test the PSE Viper SS crossbow to fully understand how their own crossbow performs.