Calculating velocity of a potato

  • #1
Hello all! Please note this is my first post and I would love to learn the method of calculating the below question... so that I may retain the knowledge and apply it for further models.
First.... the question.
How can I take the following information... and using existing data find the velocity at ejection of said projectile.
( basically I have built a pneumatic launch device and would like to...
1. Calculate the velocity I have acheived.
2. Learn the method of reaching the solution for theoretical models in future builds. )

4 inch by 36inch pressure chamber..
Pressure chamber charged to 40 PSI.
Barrel is 48 inches in length.
( reduced with check valve pic fitting that is the pressure release mechanism)
50 gram projectile.
Let's just assume 100 percent efficiency in the.release from pressure chamber to the barrel... in which the fit perfectly to the shape of barrel.
I don't know if this is relevant but friction coefficient of pvc C=150 ( cite google search)
Please let me know what formulas or known data I could use to estimate the Velocity of projectile.

Again... this may sound ignore t. Just please keep in mind I am not.simply seeking an answer... but to learn how to reach the answer and understand how and why.
Thank you all for your time and if further data is requested I will do everything to provide the requested information

Answers and Replies

  • #2
Barrel is 48 inches in length.

48 inches in length by 2 inches ( pvc. Round.)
Thanks... apologies for the missing information