Page 1 of 2 12 LastLast
Results 1 to 20 of 35

Thread: Physics Question ??

  1. #1
    Senior Member kyratshooter's Avatar
    Join Date
    Apr 2010
    Location
    KY bluegrass region-the center of the universe
    Posts
    10,365

    Default Physics Question ??

    I have been searching for the answer to this question for two days and can get nowhere. Seems you can find any information you desire on the internet unless it deals with math or physics.

    At one time I knew this stuff, but it has been 45 years since I sat in a physics classroom.

    If two identical projectiles traveling at the same velocity strike a point at the same instant is the energy of their impact multiplied or squared?
    Last edited by kyratshooter; 10-15-2015 at 11:48 PM.
    If you didn't bring jerky what did I just eat?


  2. #2

    Default

    Are you are trying to describe Kinetic energy?

    kinetic energy (E) of a massive body in motion can be calculated as half its mass (m) times the square of its velocity (v): E = ½mv2. Note that energy is a scalar quantity, i.e., it does not depend on direction, and it is always positive. When we double the mass, we double the energy; however, when we double the velocity, energy increases by a factor of four.

    from

    http://www.livescience.com/46278-kinetic-energy.html
    "But when a long train of abuses and usurpations, pursuing invariably the same Object evinces a design to reduce them under absolute Despotism, it is their right, it is their duty, to throw off such Government, and to provide new Guards for their future security.--Such has been the patient sufferance of these Colonies; and such is now the necessity which constrains them to alter their former Systems of Government."

    ~~Declaration of Independence

  3. #3
    Administrator Rick's Avatar
    Join Date
    Nov 2007
    Location
    Central Indiana
    Posts
    58,828

    Default

    I think, technically, the answer is: Increased.

  4. #4
    Senior Member Old GI's Avatar
    Join Date
    Sep 2009
    Location
    Dunnellon, FL
    Posts
    1,783

    Default

    Physics are good if used sparingly. I maintain pretty good regularity ....... oh, nevermind.
    When Wealth is Lost, Nothing is Lost;
    When Health is Lost, Something is Lost;
    When Character is Lost, ALL IS LOST!!!!!!!

    Colonel Charles Hyatt circa 1880

  5. #5

    Default

    If two identical projectiles traveling at the same velocity strike a point at the same instant is the energy of their impact multiplied or squared?
    Since they are separate and really cannot strike the exact same point at the exact same time, it is a hypothetical. But, if you did make them combine and strike the same point at the same time. And since their velocity is the same, you have only doubled the mass.

  6. #6
    Resident Wildman Wildthang's Avatar
    Join Date
    Dec 2011
    Location
    Ohio
    Posts
    3,825

    Default

    Multiplied X2

  7. #7
    Senior Member hunter63's Avatar
    Join Date
    Jul 2009
    Location
    SE/SW Wisconsin
    Posts
    26,866

    Default

    OMG....Just had a FLASHBACK...I was told that there would be no maff........(60's were a be-atch)....

    Y'all let me know what you decide........
    Need to go out a rake some leaves.....
    Geezer Squad....Charter Member #1
    Evoking the 50 year old rule...
    First 50 years...worried about the small stuff...second 50 years....Not so much
    Member Wahoo Killer knives club....#27

  8. #8

    Default

    If 2 cars hit head on at 50 mph, they both experience the same energy as hitting a brick wall at 50 mph, if that helps.

    Sent from my XT1254 using Tapatalk

  9. #9
    Senior Member hunter63's Avatar
    Join Date
    Jul 2009
    Location
    SE/SW Wisconsin
    Posts
    26,866

    Default

    So I said into the phone.....

    "Siri....If two identical projectiles traveling at the same velocity strike a point at the same instant is the energy of their impact multiplied or squared?"

    Siri said, "How the heck would I know?...you think I'm a computer or something?"

    (snort, giggle....Sorry couldn't resist....)
    Geezer Squad....Charter Member #1
    Evoking the 50 year old rule...
    First 50 years...worried about the small stuff...second 50 years....Not so much
    Member Wahoo Killer knives club....#27

  10. #10
    Senior Member kyratshooter's Avatar
    Join Date
    Apr 2010
    Location
    KY bluegrass region-the center of the universe
    Posts
    10,365

    Default

    Hey, there is a practical side I'm dealing with...

    Trying to work up the energy transferred by a buckshot load based on how many of what sized pellets strike the target.

    It is the continuation of an open choke vs. tight choke discussion on a tacticool shotgun forum.

    Yes I occasionally stray from the flock.
    Last edited by kyratshooter; 10-16-2015 at 02:00 PM.
    If you didn't bring jerky what did I just eat?

  11. #11
    Administrator Rick's Avatar
    Join Date
    Nov 2007
    Location
    Central Indiana
    Posts
    58,828

    Default

    Oh, well, heck. If it's for a forum any answer will do. Lemme think about it....doubled.

  12. #12
    Senior Member kyratshooter's Avatar
    Join Date
    Apr 2010
    Location
    KY bluegrass region-the center of the universe
    Posts
    10,365

    Default

    Yep, after this discussion I am pretty much convinced that I can put down any numbers I want and no one will say anything for fear of having to do square route to prove me wrong!

    I am closing in on realizing that the impacts are multiplied rather than squared. If they were squared/cubed/quadrupled... the impact of 5-6 buckshot would propel the target into low earth orbit.

    I already brought down one space shuttle shooting a lodged ramrod out of a CVA Blazer rifle, I don't need another incident.
    If you didn't bring jerky what did I just eat?

  13. #13

    Default

    If two cars hit head on doing the same speed, the force is doubled. Not a brick wall. Trick physics question. Do the math.
    If we are to have another contest in…our national existence I predict that the dividing line will not be Mason and Dixon's, but between patriotism & intelligence on the one side, and superstition, ambition & ignorance on the other…
    ~ President Ulysses S. Grant

  14. #14
    Super Moderator crashdive123's Avatar
    Join Date
    Jan 2008
    Location
    North Florida
    Posts
    44,844

    Default

    Krat - just tell them the force is multiplied by a factor of 3.87 and act like you mean it. Before long you will be reading all over the internet.
    Can't Means Won't

    My Youtube Channel

  15. #15
    Senior Member hunter63's Avatar
    Join Date
    Jul 2009
    Location
    SE/SW Wisconsin
    Posts
    26,866

    Default

    Quote Originally Posted by crashdive123 View Post
    Krat - just tell them the force is multiplied by a factor of 3.87 and act like you mean it. Before long you will be reading all over the internet.
    ...........from this day forward......Bhohahaha
    Geezer Squad....Charter Member #1
    Evoking the 50 year old rule...
    First 50 years...worried about the small stuff...second 50 years....Not so much
    Member Wahoo Killer knives club....#27

  16. #16
    Senior Member natertot's Avatar
    Join Date
    Aug 2011
    Location
    SW Ohio
    Posts
    4,004

    Default

    Kyrat, in the instance of your initial post, the energy is simply doubled. If it were three projectiles, it would be tripled. Four would be quadrupled and so on. This is strictly on the projectile side of things. The force of impact is not as linear as the energy however. Think about a shotshell containing 1 oz of #8 vs a 1 oz slug. Both contain the same about of weight of the same metal, but the force of the slug is much greater because it is concentrated. Same thing with your OP. More projectiles will cause greater damage, but fewer projectiles with more mass will cause even greater damage yet.

    Sorry, there is no clear cut answer as there are too many variables and I am not certain what the exact specifics are.
    ”There's nothing glorious in dying. Anyone can do it.” ~Johnny Rotten

  17. #17
    Senior Member kyratshooter's Avatar
    Join Date
    Apr 2010
    Location
    KY bluegrass region-the center of the universe
    Posts
    10,365

    Default

    It was just one of the age old discussions about the craze for cylinder bore home defense shotguns.

    The old thing where those that have never fired a shotgun think that they are going to hit/kill five people with one pellet each and the ones that have fired a shotgun and know that you want all the buckshot to hit one target will all the force available.

    Just the normal forum stuff. But I wanted to give them the razzle dazzle with the math and shut them up, or at least scare them with long division and powers of 10.

    Working up the numbers it takes two pellets of #00 buckshot to equal one 125gn 9mm/38spl impact, so unless you hit a vital organ or penetrate to the central nervous system with one of those pellets you better hope you get lots of them on target, because individually they do not have much in the way of stopping power.

    There is a theory of multiple impact trauma that claims that when you are hit by numerous projectiles at the same instant the reaction of the body is different than if they are spread out over a time frame. It is one of the philosophies behind the use of the "double tap" in combat handgun training. There was a lot written about it back in the ancient days of the 1970s, but I can find none of the articles now.
    Last edited by kyratshooter; 10-17-2015 at 03:09 AM.
    If you didn't bring jerky what did I just eat?

  18. #18
    Senior Member 2dumb2kwit's Avatar
    Join Date
    Jun 2009
    Location
    Northeastern NC
    Posts
    8,530

    Default

    Home defense? If you are trying to figure out what choke to use to stop a home invader.........how big are your rooms? Hahahaha.

    (Y'all must have a much bigger house, than I have.) LOL
    Writer of wrongs.
    Honey, just cuz I talk slow doesn't mean I'm stupid. (Jake- Sweet Home Alabama)
    "Stop Global Whining"

  19. #19
    Administrator Rick's Avatar
    Join Date
    Nov 2007
    Location
    Central Indiana
    Posts
    58,828

    Default

    Quote Originally Posted by natertot
    Kyrat, in the instance of your initial post, the energy is simply doubled.


    See that? Post 11. And you ya'll thought I was just another pretty face.

  20. #20
    Senior Member kyratshooter's Avatar
    Join Date
    Apr 2010
    Location
    KY bluegrass region-the center of the universe
    Posts
    10,365

    Default

    Quote Originally Posted by 2dumb2kwit View Post
    Home defense? If you are trying to figure out what choke to use to stop a home invader.........how big are your rooms? Hahahaha.

    (Y'all must have a much bigger house, than I have.) LOL
    The house is not big, but down the hall, bedroom to back door, I have 60 feet/20 yards.

    I have also been known to take the shotgun outside when something is in the chicken house or a known coyote type varmint is lurking about. I have 37 yards to the back fence and about 30 yards to each side of the yard.

    Either of those situations needs some choke to keep things all in the same general area and effective.

    While the "riot gun" with 18" barrel can be effective at the extreme close ranges of the indoor arena, not having a choke restricts the weapon to only extreme short range use and makes it useless for what the industry has worked so hard for the past 150 years to develop.

    It has also created a widespread myth that the shotgun is no good for anything past 20 yards and useless for anything but indoor home defense. While that might be true for THEIR shotguns, it is not true for mine, or anyone else that has a modified or full choke or choke tube in their pea shooter.
    If you didn't bring jerky what did I just eat?

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •