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Rad Mrdal
Guest
Hey Champ, you've missed the crucial words in the post such as ( hypothetically in the theory). Rad
Lynn: I knew the info was dated....just didn't want anyone reading this thread to think that professional Drag Racing was still stuck with '80s technology. 
When people realize that a nitromethane Top Fuel/Funny Car powerplant makes as much horsepower in one cylinder as an entire Formula One engine....it brings it into perspective.
And NASCAR rigs are positively anemic by comparison. 'Course...NASCAR as a whole sucks huge anyway. Might be a pun there.
Now back to our regularly scheduled programming.......
When people realize that a nitromethane Top Fuel/Funny Car powerplant makes as much horsepower in one cylinder as an entire Formula One engine....it brings it into perspective. And NASCAR rigs are positively anemic by comparison.
'Course...NASCAR as a whole sucks huge anyway. Might be a pun there. Now back to our regularly scheduled programming.......
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Dew
Guest
This has been a most interesting thread... All I want to know is if I get in stuck in 4 wheel drive, how many shots with my rifle do I have to take to get me out of the mud? I guess I would have to have a buddy sit in the bed of the truck and shoot to the rear so I could use the extra horsepower to push me out onto dry dirt.
Bill Wynne
Active member
One last time in case you missed it.
No matter how you cut it, the definition of a horsepower is the amount of work required to lift 550 pounds one foot in one second (550 foot pounds per second). To move your tiny bullet 3000 feet per second (that is 3000 feet in a second), you need about 90 foot pounds produced in a in a second. There you have it, a known weight, a known distance, and a known time.
Just concentrate on those numbers. That is all there is to it. Way less than one horsepower.
Don't worry about the dragster in your driveway or the engine in an aircraft carrier. They have nothing to do with the problem.
There now, now that I have explained it again, don't you feel better.
Concho Bill
No matter how you cut it, the definition of a horsepower is the amount of work required to lift 550 pounds one foot in one second (550 foot pounds per second). To move your tiny bullet 3000 feet per second (that is 3000 feet in a second), you need about 90 foot pounds produced in a in a second. There you have it, a known weight, a known distance, and a known time.
Just concentrate on those numbers. That is all there is to it. Way less than one horsepower.
Don't worry about the dragster in your driveway or the engine in an aircraft carrier. They have nothing to do with the problem.
There now, now that I have explained it again, don't you feel better.
Concho Bill
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Vibe
Guest
No matter how you cut it, the definition of a horsepower is the amount of work required to lift 550 pounds one foot in one second (550 foot pounds per second). To move your tiny bullet 3000 feet per second (that is 3000 feet in a second), you need about 90 foot pounds produced in a in a second. There you have it, a known weight, a known distance, and a known time.
Just concentrate on those numbers. That is all there is to it. Way less than one horsepower.
There now, now that I have explained it (incorrectly) again, don't you feel better.
Concho Bill
They are not the ones that missed it Bill.
Bill Wynne
Active member
Now Vibe,
If you won't mention that kinetic energy thing, I won't mention anything about Arkansas physics. (I know that is not fair. I am just joking)
Concho Bill
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Vibe
Guest
LOL. That "Kinetic energy thing" as you so eloquently phrased it - it a major part of the definition of Power, and thus horsePower. I'm sorry to inform you that you simply cannot have the one without the other.Now Vibe,
If you won't mention that kinetic energy thing, I won't mention anything about Arkansas physics. (I know that is not fair. I am just joking)
Concho Bill
Bill Wynne
Active member
I think you are wrong, my friend.
Just for grins, using your formulas consider your bullet to be twice it's weight and the velocity being 1/2 of what is was. You will have the same number of foot pounds per second, therefore the same horsepower by definition. However, you will have a different amount of kinetic energy.
Trust me, just try it. If you can prove to me that I am wrong, I will say so.
Concho Bill
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longshooter
New member
This has been a most interesting thread... All I want to know is if I get in stuck in 4 wheel drive, how many shots with my rifle do I have to take to get me out of the mud? I guess I would have to have a buddy sit in the bed of the truck and shoot to the rear so I could use the extra horsepower to push me out onto dry dirt.
Why don't you have him fire 588 times, in the space of one second, and we'll see if this gets you out. Maybe he should wear an extra shirt.
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Vibe
Guest
The opinion of 10,000 men is of no value if none of them know anything about the subject.I think you are wrong, my friend.
- Marcus Aurelius
Actually you will have 1/2 the Ft-lbs of energy in that scenario. And power is defined as the change in energy (Energy, not momentum) divided by the time it took to enact the change.
I have. Several times. And you still haven't.
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Bill Wynne
Active member
Vibe, You have been wrong several times, but I have not given up on you.
This is the definition of a horse power.
1 hp ≡ 33,000 ft·lbf/min by definition
= 550 ft·lbf/s since 1 min = 60 s
Do you see anything about kinetic energy in that definition.
Concho Bill
Bill Wynne
Active member
Guys,
The definition of what a horsepower is was based on how much work a mill horse could do. I don't think it is a very good way to state the power of a rifle. It can be, however, a good comparison measure of an engine.
I will say that Montana Pete offered a good mind twisting question. My 50 year old college physics book (which I saved) offers less than a paragraph and a drawing of a horse to the subject of horsepower lifting a 550 pound weight to the subject. The author must have thought that covered it.
Concho Bill
The definition of what a horsepower is was based on how much work a mill horse could do. I don't think it is a very good way to state the power of a rifle. It can be, however, a good comparison measure of an engine.
I will say that Montana Pete offered a good mind twisting question. My 50 year old college physics book (which I saved) offers less than a paragraph and a drawing of a horse to the subject of horsepower lifting a 550 pound weight to the subject. The author must have thought that covered it.
Concho Bill
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Vibe
Guest
Guys,
The definition of what a horsepower is was based on how much work a mill horse could do. I don't think it is a very good way to state the power of a rifle. It can be, however, a good comparison measure of an engine.
I will say that Montana Pete offered a good mind twisting question. My 50 year old college physics book (which I saved) offers less than a paragraph and a drawing of a horse to the subject of horsepower lifting a 550 pound weight to the subject. The author must have thought that covered it.
Concho Bill
Please refer back to post 107 of this thread
http://www.benchrest.com/forums/showpost.php?p=450092&postcount=107
Work equals a change in ENERGY - Potential, Kinetic, Thermal....doesn't matter, could be all of one or the other or a mixture of any or all (which is most often the case). If the ENERGY was changed, work was done. Either TO an object if the energy increased or BY the object if it decreased.
Power is determined by how much time it took to do said amount of Work. Horsepower is simply a unit used to measure Power.
By your calculations how much higher off the ground should a 3000hp dragster be after a 4 second run? And yet it remains on the ground (if the driver is lucky and all goes as planned) and only gains Velocity really rapidly.
I would wager that even your 50 year old Physics book has a good chapter on Power.
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moemag
Guest
Holy Thread Resurrection!
It just so happens I am an Aerospace engineer who happens to work at a certain company that makes very impressive electric Gatling guns, who happened to come across this thread doing some research. So just in case your still interested…
Yes, you can take any load you want with any rifle you want and figure out how much horsepower the RIFLE makes.
The rifles FREE (felt) RECOIL is measured in foot-pounds. I don’t know why you all are so concerned with the external ballistics of the round LOL! It looks like one or two may have figured this out… but I don’t think it caught on. I honestly didn’t read all the posts. If you want to find out how much horsepower the round creates... thats another question.
Once you figure out what that is, which is where your F=1/2MV^2 comes in
Look at this page to figure that out...http://en.wikipedia.org/wiki/Free_recoil
But being that a single gun shot is so short... we kind of assume it’s instantaneous and it’s just a force applied and there is no horsepower. But if you really want to divide the (recoil force)/ (time it takes for the round to leave the barrel) then you could find some* amount of horsepower.
Where it comes in handy for me is when my guns are shooting at over 40 rounds per second. in which case the rate of fire will allow for a useful reason to know horsepower.
In which case the M134d makes about 16.4 (and upwards to 22) horsepower when shooting.
Enjoy.
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*Edit, on second look, it may not be very smal
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Bill Wynne
Active member
There now, see I was right!
And I don't even know Dr. Moemag. Thanks anyway.
Concho Bill
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Vibe
Guest
Not even close. First off his 16.4 HP is the net result of 40 very short high HP impulses (and 40 relitively long "rest" periods) during each second. This was not the question. The other thing is that he is working off of the "free felt recoil" of the rifle, and while the HP is "felt" on that end as well, the velocity measurement is a best guess based upon calculations from the measured velocity of the bullet. The question was
That would have to be per single shot. The fact that he can scavange 16.4 HP from the gun to do other work is actually immaterial to the problem.
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I think that the confusion here lies in the terms "generated," "rated" and "produces."
The challenge question uses "generated" which to me means actual work done.
........"to me means"...... herein lies the problem, we're each interpreting the (poorly structured?) original question differently.
To illustrate, I agree totally with vibe's last post yes "The fact that he can scavange 16.4 HP from the gun to do other work is actually immaterial to the problem. "
al
The challenge question uses "generated" which to me means actual work done.
........"to me means"...... herein lies the problem, we're each interpreting the (poorly structured?) original question differently.
To illustrate, I agree totally with vibe's last post
yes "The fact that he can scavange 16.4 HP from the gun to do other work is actually immaterial to the problem. "al
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moemag
Guest
Calculating the horsepower of my minigun is no different form the way a car sums up a whole bunch of relatively short cylinder bursts that occur in a given time frame to give horsepower of an engine. Yeah its not perfect. but thats what we do.
I offered a method. With an example.
Horsepower is force/time.
Horsepower of a rifle would be (force of the rifle)/ (time that the force is acting upon the rifle.)
Force of rifle = recoil however you define it.
I used free recoil because it is easy enough to determine. Sure if you want to take into account muzzle breaks, soft shoulders and limp wrists… it’s not going to be perfect, but it will be close.
Time that the force is acting upon the rifle= just what it is… but there are a lot of nasty little calculus things that come into play to figure that out.
Basically… finding the horsepower created of a single shot rifle is pointless. You have a foot-pound force, that’s sufficient enough is it not?
Here ya go. If you want to know how much horsepower a rifle can generate...
Next time your at the range, shoot from a shopping cart on a ramp of a given angle, weigh the cart with you and your rifle in it, and see how far it rolls up the ramp, all the while timing from fire till you stop rolling. If ya really want to get complex, throw in a wheel to ramp friction coefficient.
I offered a method. With an example.
Horsepower is force/time.
Horsepower of a rifle would be (force of the rifle)/ (time that the force is acting upon the rifle.)
Force of rifle = recoil however you define it.
I used free recoil because it is easy enough to determine. Sure if you want to take into account muzzle breaks, soft shoulders and limp wrists… it’s not going to be perfect, but it will be close.
Time that the force is acting upon the rifle= just what it is… but there are a lot of nasty little calculus things that come into play to figure that out.
Basically… finding the horsepower created of a single shot rifle is pointless. You have a foot-pound force, that’s sufficient enough is it not?
Here ya go. If you want to know how much horsepower a rifle can generate...
Next time your at the range, shoot from a shopping cart on a ramp of a given angle, weigh the cart with you and your rifle in it, and see how far it rolls up the ramp, all the while timing from fire till you stop rolling. If ya really want to get complex, throw in a wheel to ramp friction coefficient.
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Vibe
Guest
I expected better.
Horsepower is NOT force/time. Horse power is ENERGY/time
Lets just use published muzzle energy divided by time in barrel.
Barrel length/((Muzzle vel-initial vel)/2)
Barrel length divided by average velocity will be "close enough".
Nope. Force is in pounds - torque and energy are in Foot-pounds and pound- feet
Balistic pendulum = method of measuring momentum...Again..Not energy.
Horsepower is the CHANGE in ENERGY over a period of TIME.
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