Recent content by RobRobinette

Thank you Dale, I think you finally got through, that makes sense to me. Again, thank you everyone for the help.

MyMass * Velocity^2 / 2g = MyEnergy "The rate at which you gain energy over time increases if your velocity is higher. But the rate at which you gain energy over distance stays the same." How do we square this nonlinear equation with Jbriggs time and distance statement? A related question...

Thanks everyone, that makes sense but I still don't understand how the velocity squared in the energy equation does not come into play. When I used to aero brake the F-15 I always assumed the relationship between velocity, energy and the start of foot braking was nonlinear.

I ride gravel bikes on steep mountain roads and on the way down I have to ride the brakes pretty hard. I want to minimize brake heat so I have always thought that keeping the bike's velocity lower on average by applying the brakes more often will reduce the amount of energy the brakes will have...

jbriggs, I was thinking in terms of energy transfer and not in terms of work. I forgot you can expend energy trying to move something that doesn't move and no work is done. Thanks again for the excellent help.

Thank you very much hutch for clearing up the relationship between gun weight, gun recoil and muzzle velocity.

I think I understand your work and impulse explanation. In the example where the gun and bullet weigh the same, 1/2 of the energy of the expanding gasses is used to move the gun and half is used to move the bullet and equal work is done between them. If we fix the gun against a wall then no work...

If it is not momentum then what energy is transferred from the gun to the bullet when the gun is restrained by the metal wall?

A.T., I'm trying to understand the basic physics involved. Can someone show an equation that shows the transfer of energy or momentum from the gun side of the equation to the bullet side? For example, if we cut the gun recoil momentum in half by restraining its movement would most of that...

Thank you Nugatory for the help. What I'm working on is trying to determine if the hold of a pistol has a measurable effect on bullet velocity. With a lightweight pistol with a strong recoil, like a titanium 357 Magnum revolver, will you lose bullet velocity with a frail person holding the...

A.T., can you expand on that? How would that fit into the momentum equation?

So the upper bound would be a doubling of the bullet velocity, correct? We would lose some energy to heat generated by the shock wave in the metal pistol frame and metal wall, correct? Any way to estimate that energy loss?

3300k seems to be a good estimate of propellant gas temperature during the first half of bullet travel and around 3000k when the bullet is at 4 " (at the muzzle of the 4" long barrel). Can we determine the original question with this new info?

I used QuickLOAD, an internal ballistics calculator, to calculate some in-barrel bullet speeds. For a 357 Magnum pistol with a 4 inch barrel firing a 180 grain bullet, the bullet is going 200 ms at 2 inches down the barrel and 291 ms at the 4" muzzle. I googled the speed of sound through metal...

Yes, I see. The effect has to travel through the frame of the gun then through the hot propellant gasses to reach the bullet.