finding force using volume and psi HELP!!!
Welcome to SpudFiles.
Force on what from what? This post is very vague. Describe what you want in more detail.
Force on what from what? This post is very vague. Describe what you want in more detail.
All spud gun related projects are currently on hold.
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MrCrowley
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Force = Pressure x Areakydavies wrote:how can you find the force in Newtons without using kinematics and only using the size of your air tank and what psi its at?
Force in Pounds
Pressure in Pounds per Square Inch
Area in Inches
So if your barrel is 2" in diameter (pi x 1^2) = 3.14 inches^2 and has 100PSI in it, assuming the projectile is a good fit in the barrel, there will be 314 pounds of force on the projectile.
edit: Then convert that to Newtons.
I bet he's trying to find out the kinetic energy from when the round strikes a target.
What's the poll up to?
To answer the question properly, however, you should do what btrettel suggests. A good start for you, though, is to learn and use GGDT.
What's the poll up to?
To answer the question properly, however, you should do what btrettel suggests. A good start for you, though, is to learn and use GGDT.
Volume of air tank has no effect on force on the internals, just surface area and pressure. What are you trying to find? A certain force on part of the internals? If the materials you are using for your chamber will hold?
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SpudBlaster15
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Last edited by SpudBlaster15 on Wed Jul 14, 2021 7:54 pm, edited 1 time in total.
sorry about the vague question but i built a 9' tall potato cannon and i have no safe place to shoot it thats near by so i cant time how long the potato is in the air for so kinematics is out. i needed to find the buzzel velocity of the cannon without firing it. to do that i need the force the pneumatic chamber exerted on the potato so that i could use F=ma to find the acceleraion then multiply it by my barrel length (10'). thanks for the help MrCrowley 
Assuming that the 70 psi stays constant after you open whatever valve it is (which it doesn't, especially as the spud travels down the barrel, it may be worth it to calculate the jerk because the number I will supply here is greater than actual), the spud experiences an acceleration of 2.51 m/s^2.
Area of spud acted on by pressure- 0.00114 m^2
Area of spud acted on by pressure- 1.77 in^2
Force experienced by spud- 123.7 lbs
Force experienced by spud- 550.24 N
Acceleration of spud- 2,200 m/s^2
Muzzle velocity of spud- 118.7 m/s
That's the best I can do for you, since I don't know how to account for the depressurization behind the spud as it travels down the barrel. I would need to know your chamber volume to calculate that- not that I'm sure I could.
Please remember, THE MUZZLE VELOCITY IS INFLATED. Given the chamber volume, I will do my best to give a better approximation.
EDIT: I cannot supply the maths for a varying force, which is exactly what would be exerted on the spud as it travels down the barrel, since I am unfamiliar with calculus. I sure could probably find a friend to do so for me, if you are willing to wait.
Area of spud acted on by pressure- 0.00114 m^2
Area of spud acted on by pressure- 1.77 in^2
Force experienced by spud- 123.7 lbs
Force experienced by spud- 550.24 N
Acceleration of spud- 2,200 m/s^2
Muzzle velocity of spud- 118.7 m/s
That's the best I can do for you, since I don't know how to account for the depressurization behind the spud as it travels down the barrel. I would need to know your chamber volume to calculate that- not that I'm sure I could.
Please remember, THE MUZZLE VELOCITY IS INFLATED. Given the chamber volume, I will do my best to give a better approximation.
EDIT: I cannot supply the maths for a varying force, which is exactly what would be exerted on the spud as it travels down the barrel, since I am unfamiliar with calculus. I sure could probably find a friend to do so for me, if you are willing to wait.
