What is the formula for pellet energy at the muzzle of a air rifle using the chrony ?
pellet energy
- Thread starter smooth.pull
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Energy is calculated as follows:
Velocity (fps) * Velocity (fps) * Pellet Weight (grains) / 450240 = Energy (ft-lbs)
Velocity is calculated as follows:
The square root of (Energy (ft-lbs) * 450240 / Pellet Weight (grains)) = Velocity (fps)
Velocity (fps) * Velocity (fps) * Pellet Weight (grains) / 450240 = Energy (ft-lbs)
Velocity is calculated as follows:
The square root of (Energy (ft-lbs) * 450240 / Pellet Weight (grains)) = Velocity (fps)
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Actually you have an error in your formula, it should read as follows:
(Velocity (fps) * Velocity (fps) * Pellet Weight (grains) )/ 450240 = Energy (ft-lbs)
The Velocity and Grains, must be calculated before you divide by 45020.
Cheers,
Brian
(Velocity (fps) * Velocity (fps) * Pellet Weight (grains) )/ 450240 = Energy (ft-lbs)
The Velocity and Grains, must be calculated before you divide by 45020.
Cheers,
Brian
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It doesn't make any difference. Dividing by 45020 is the same as multiplying by 1/45020, and multiplication is commutative.
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Earlier this year I was wondering "just what is a foot pound?" Couldn't find the answer anywhere. Of course a foot pound as it relates to torque is easy to grasp. One pound of force applied one foot away from the vertex is one foot pound of torque. But what is a foot pound of energy?
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Think of a one pound weigh floating in the air. One foot pound is the energy required to move that one pound weight one foot in distance.
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Now figure out how many PSI that is at the point of impact, assuming a .25cal pellet with a flat wadcutter style head pushing 40ft/lbs energy.
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[/quote]
Think of a one pound weigh floating in the air. One foot pound is the energy required to move that one pound weight one foot in distance.[/quote]
Very close.
The energy required to move the one pound weight in what direction?
Think of a one pound weigh floating in the air. One foot pound is the energy required to move that one pound weight one foot in distance.[/quote]
Very close.
The energy required to move the one pound weight in what direction?
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If you can't explain it simply you don't understand it well enough.
-Albert Einstein-
Drop a 1 pound mass 1 foot and it generates 1 foot pound of momentum.
I can't find any explanation describing that anywhere on the whole damn internet. Just formulas and calculators. All the formulas I've seen are in grains so I had to figure out what a grain is too.
7,000 grains = 1 pound
Free fall rate is 32 feet per second squared.
Knowing those 2 facts I worked the formula backwards starting with a 1 ft lb result and using a 7,000 grain projectile comes out to ~8~ feet per second which is the final speed of a 1 foot free fall.
-Albert Einstein-
Drop a 1 pound mass 1 foot and it generates 1 foot pound of momentum.
I can't find any explanation describing that anywhere on the whole damn internet. Just formulas and calculators. All the formulas I've seen are in grains so I had to figure out what a grain is too.
7,000 grains = 1 pound
Free fall rate is 32 feet per second squared.
Knowing those 2 facts I worked the formula backwards starting with a 1 ft lb result and using a 7,000 grain projectile comes out to ~8~ feet per second which is the final speed of a 1 foot free fall.
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Note for "force," use this formula:
F = ma
F = Force
m = mass
a = acceleration
When item A hits item B the force of item A on B is equal to item A's mass times how quickly it decelerates upon hitting mass B.
Try not to get confused about acceleration, deceleration is actually acceleration in a "negative" direction relative to the "flight" of an item.
If item A, an air gun pellet, hits a very solid non-pliable item B, a huge anchored hunk of steel, the force will be "high" relative to A hitting a large Jello blob.
Find an explanation of the difference between energy and force here:
http://www.differencebetween.com/difference-between-energy-and-vs-force/
F = ma
F = Force
m = mass
a = acceleration
When item A hits item B the force of item A on B is equal to item A's mass times how quickly it decelerates upon hitting mass B.
Try not to get confused about acceleration, deceleration is actually acceleration in a "negative" direction relative to the "flight" of an item.
If item A, an air gun pellet, hits a very solid non-pliable item B, a huge anchored hunk of steel, the force will be "high" relative to A hitting a large Jello blob.
Find an explanation of the difference between energy and force here:
http://www.differencebetween.com/difference-between-energy-and-vs-force/
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Ok, now let's look at Energy
Formula is E = 1/2mv^2 * 1/225217.5
E = Energy (ft lbs)
m = Mass (grains)
v = Velocity (ft/s)
225217.5 is a constant that converts the grains units to lbs and accounts for gravity
Note: ^2 means the value is squared
225217.5 = 1 ft lbs / (7000 gr * 32.163 ft^2/s^2)
7000 gr per lb
Acceleration of gravity 32.163 ft^2/s^2
E = 1/2 m (gr) * v^2 (ft^2/s^2) * 225217.4 (ft lbs) / (ft^2/s^2)
Simplifies to:
E = mv^2 / 450435 (ft lbs)
Formula is E = 1/2mv^2 * 1/225217.5
E = Energy (ft lbs)
m = Mass (grains)
v = Velocity (ft/s)
225217.5 is a constant that converts the grains units to lbs and accounts for gravity
Note: ^2 means the value is squared
225217.5 = 1 ft lbs / (7000 gr * 32.163 ft^2/s^2)
7000 gr per lb
Acceleration of gravity 32.163 ft^2/s^2
E = 1/2 m (gr) * v^2 (ft^2/s^2) * 225217.4 (ft lbs) / (ft^2/s^2)
Simplifies to:
E = mv^2 / 450435 (ft lbs)
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You got it brother.
Now to explain it simply.
The units in "foot pounds" describe the amount of momentum an object has based on it's mass and velocity.
It takes one foot pound of energy to propel a one pound mass one foot up from it's resting place.
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