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Calculate Pellet Kinetic Energy and Momentum for Air Guns

Kinetic Energy is frequently used to compare the "power" of various airguns.
Momentum, less frequently used, may be useful in certain situations.

Calculate pellet Energy
and Momentum
  1. Enter the pellet weight in grains
    .
  2. Enter Velocity in ft/sec
    .
  3. Press 'Calculate
Pellet
Weight
(grains) 		Velocity
(feet/sec)
Energy
(ft-lbs) 		Momentum
(ft-lbs / second)
Kinetic Energy is equal to one half the Mass times the square of the Velocity
or in mathematical notation:
Kinetic Energy = ½ x Mass x Velocity 2

We are used to seeing Velocity in feet per second (ft/sec) and pellet weight listed in grains (gr.)
To convert Weight to Mass we must divide the pellet weight by 7000 gr. per pound and divide the result by the acceleration due to gravity.
so:
Mass = pellet Weight in grains ÷ 7000 grains / pound ÷ 32.175 ft/sec/sec
Therefore:
Kinetic Energy = ½ x Weight Velocity 2  ÷ 7000 ÷ 32.175


This simplifies to:
Kinetic Energy = Weight x Velocity 2  ÷ 450450


Momentum is equal the Mass times the Velocity
or in mathematical notation:
Momentum = Mass x Velocity

This simplifies to:
Momentum = Weight x Velocity ÷ 225225

Special thanks to our friends at Bit1 for their assistance with this project.

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