Here’s the formula for calculating your bow‘s kinetic energy output: Fps 2 X Weight of Arrow / 450,240 = Arrow’s Kinetic Energy. Using the arrow weight and speed, calculate the KE and momentum. and 28″ draw) will result in 51.17 ft-lbs of kinetic energy. 450240 is a constant, you will need to know how fast your bow is, and how much your arrow weighs. The only way to make an arrow go quicker (any given bow ) is make your arrows lighter. Use the straight-line distance to the target. Grim Reaper Broadheads is the inventor of Razortip Technology - patented mini-tip blade(s) that greatly enhance penetration. Kinetic energy is expressed in the formula M x V squared ÷ 450240 = E in pound feet. Our new practice heads are available now as well as our new crossbow broadheads, designed specifically for 400 fps and faster crossbows. Here’s an example of determining the kinetic energy of a bow shooting a 400 grain arrow with a 100 grain broadhead at 250 fps: KE= 250 2 x 500 / 450,240 Arrow Kinetic Energy (KE) and Momentum Calculator. They are various formulas with different implications. KE=0.5xMV squared. Use the kinetic energy calculator to find out how fast that the same bullet will have to be traveling at to get its energy to 1 J. In our above example, we’ve calculated Kinetic Energy to be 51.7 ft-lbs. M is Mass (weight in grains), V is Velocity in feet per second, and E is kinetic energy in foot pounds. Kinetic energy isn't momentum. This means that the Kinetic Energy of a 400 grain arrow, shot from your specific bow using our example’s specific settings (50 lbs. This is the distance needed for the calculation. By drawing your bow, you convert mechanical energy (ME) and store it as potential energy (PE) in the bow limbs. You can calculate your arrow's KE and express it in foot-pounds. This form will calculate the kinetic energy of your arrow, even if you don't know your arrow's speed. Kinetic Energy Calculator Enter any two of the following values, then press the "Calculate" button: Arrow Weight (grains) Arrow Velocity (fps) Kinetic Energy (ft.lbs.) Calculate arrow FOC (front of center) using two simple measurements and the balance point of the arrow. 650 Grains is the heavy bone beginning. You simply need to enter the information in the form below, and your speed will be estimated to within a few FPS. Welcome to the Kinetic Energy Calculator. The kinetic energy of this setup would be calculated by taking the arrow weight of 400, multiplying that by the speed of 297-squared, and dividing the result of that multiplication by 450,800 – which tells us that this bow and arrow setup produces 78 ft. lbs of kinetic energy. Kinetic Energy Deterioration Rate. One, for example, states that 55 foot pounds (ft … It's a velocity of about 20 m/s. In this example, a guesstimated angle of 45 degrees and a 28 yard straight line distance will require an aiming distance of 19.8 yards. Kinetic energy relies on the grain of the arrows and the speed of the crossbow. When you pull the trigger most of that PE is transferred to the arrow and converted to kinetic energy (KE), which propels it downrange. That's the reason why bullets cause a lot of damage while hitting targets. They work together to determine the energy that the arrow emits when it leaves the crossbow and heads for its target. Consider momentum when bow poundage gets below 60#. Among archers, I see and hear a lot of discussions about the kinetic energy (KE) of arrows. The only way to move a heavier arrow quicker is with more bow poundage. Arrow FOC (front of center) Calculator. Its kinetic energy equals 2,500 J, way above 1 J because of the considerable velocity. Even several major arrow manufacturers have KE calculators and recommendations for big game hunting. Bow/Arrow Speed Calculator.