My apologies if my attempt at humor seemed snarky to you.
The smiley face was meant to convey a friendly smile.
The calculation was actually in the article I asked you to read before posting
any more thoughts on the matter. I rounded the number, which is actually 99.57%,
so I was actually being a bit conservative:
The mass of the firearm () is generally much greater than the projectile mass (
) which means that most of the kinetic energy produced by the firing of the firearm is given to the projectile. For example, a rifle weighing 5 pounds firing a 150 grain bullet, the recoil energy will be only 0.43 percent of the total kinetic energy developed. In the case of zero-recoil, the firearm will gain no energy, and the energy of the projectile will be increased by 0.43 percent over that of the free-recoil case.
A clearer way to state the last sentence was my example of resting the rifle butt on
the ground and firing into the air. "The firearm will gain no energy" means that 100%
of the energy goes into the bullet and the escaping gases. Adding 0.43% to 99.57%
gives 100%, which the article could have simply stated, making it much easier to follow.
This is fairly simple physics, and fairly simple math, but this is a DIY biology thread,
and we have probably exhausted most of the interest of the group in this side-thread.
I changed the subject so people could more easily kill it if they are bored. I often
describe my job as teaching physics to people with short attention spans, and I am
afraid I may have gotten carried away this time.
:-)
-----
Get a free science project every week! "http://scitoys.com/newsletter.html"On Wed, Mar 7, 2012 at 8:07 AM, Phil <philgoetz@gmail.com> wrote:
On Mar 5, 1:46 pm, Simon Quellen Field <sfi...@scitoys.com> wrote:>...
> Physics doesn't care what makes sense to you.
> :-)
> Before replying with more intuition, consider reading about the subject:Before replying with more snarky comments,
> "http://en.wikipedia.org/wiki/Recoil"
describe the calculation you did to conclude that 99.5%
of the energy goes into the bullet.
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