Things You'll Need

Instructions

1

Weigh the arrow. To find out the arrow's kinetic energy, plug two properties of the arrow into a mathematical equation. The first is the weight. Use a scale to get an accurate reading and be sure to write it down for later.
2

Find the velocity of the arrow. You can get a rough estimate simply enough, using only a stopwatch and tape measure. Velocity is defined as "distance over time," often measured in meters/second. Fire your arrow and keep track of the time it takes to hit the ground, using your stopwatch. Next, measure the distance from the point you fired the arrow to the point it hit the ground. Write down the "distance/time," and you've just found the velocity.
3

Calculate the kinetic energy of the arrow. This can be done by taking the data you've collected and plugging it into the following equation:

1/2 times Mass times Velocity Squared

That is to say, multiply 0.5 by the arrow's mass by the squared velocity of the arrow when fired. The number you receive once the equation is calculated is the arrow's kinetic energy.