1. Attention: We have put together a thread with tips and a tutorial video to help with using the new software. Please take a moment to check out the thread here: Trapshooters.com Tutorial & Help Video.
    Dismiss Notice

how many feet per senond is 39 mph

Discussion in 'Shooting Related Threads' started by romie, Jun 22, 2010.

Thread Status:
Not open for further replies.
  1. romie

    romie Active Member

    Joined:
    Jan 29, 1998
    Messages:
    910
    Just wondering on doubles.how much difference a second or so can make.
     
  2. zzt

    zzt Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    3,462
    Location:
    SE PA
    57.2fps
     
  3. Neil Winston

    Neil Winston Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    7,848
    Except . . .

    It doesn't work for comparing target speed measured by radar guns and chronographs.

    Why? Extra credit for both reasons.

    Neil
     
  4. BFJ201

    BFJ201 TS Member

    Joined:
    Jul 25, 2007
    Messages:
    147
    The radar gun uses the Doppler effect to register a speed (the change in frequency of the radio wave as it bounces off of the measured object) - radar measures the speed at a specific time.

    The chronograph measures speed by the time it covers a specific distance which is an average speed and if the object is changing speed it will give a different reading.
     
  5. Anchorsteam

    Anchorsteam TS Member

    Joined:
    Feb 23, 2010
    Messages:
    872
    39 MPH is 57.2 FPS

    BTW: 1200 FPS is 818 MPH; 1350 FPS is 920 MPH - pretty fast
     
  6. Neil Winston

    Neil Winston Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    7,848
    OK, BFJ201 that's a great reason (I'd not thought of) but it can't account for the quite different speeds you would actually get by measuring a single target - neither system is capable of such fine-grained accuracy. You got a couple of pellets into it with imaginative analysis, but the scorer sees only dust, no visible piece, unfortunately.

    Neil
     
  7. romie

    romie Active Member

    Joined:
    Jan 29, 1998
    Messages:
    910
    I am not splitting hairs but If I take one second longer it will have moved approximately 19 yards or 57 ft.Approximately assuming it is slowing down it will be a little less
     
  8. Anchorsteam

    Anchorsteam TS Member

    Joined:
    Feb 23, 2010
    Messages:
    872
    here's on e for you...what slows down faster: the target or the shot!?!? Or the same.
     
  9. romie

    romie Active Member

    Joined:
    Jan 29, 1998
    Messages:
    910
    according to Newton the same.Although he didn't have domed targets at the time
     
  10. chipking

    chipking TS Member

    Joined:
    Jan 29, 1998
    Messages:
    1,761
    The biggest difference is that the chronograph is measuring the clay just as it leaves the trap at it's fastest speed and the radar gun measures the target some distance (variable by gun and setter) from the trap as it is slowing down.

    --- Chip King ---
     
  11. Unknown1

    Unknown1 Well-Known Member

    Joined:
    Nov 5, 2009
    Messages:
    3,402
    Remember that 1 mph is 1.466 feet/sec and multiply from there.

    MK
     
  12. hmb

    hmb Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    9,434
    Which ever object encounters the greater air resistance slows down faster. HMB
     
  13. GrubbyJack

    GrubbyJack Member

    Joined:
    Jul 19, 2006
    Messages:
    527
    ie::: ballistic coefficient (BC) an object ability to overcome air resistance in flight....wonder what the BC of a clay target would be????Grubby
     
  14. wolfram

    wolfram Well-Known Member

    Joined:
    Jul 17, 2007
    Messages:
    6,266
    +
    The acceleration of the shot is much greater than for the target both in being launched and being slowed by air friction. Acceleration is also known as the change in velocity with respect to time. So the shot looses velocity at a much greater rate than the target.

    The applicable Newtonian therory in this case is that the acceleration due to gravity is a constant and affects the target and the shot equally. Gravity is that nasty downward force that doesn't always appear to be a constant because different objects experience different amounts of counterbalancing drag while passing through air. An example would be two guys jumping out of an airplane at the same time at 5,000 feet agl. One deploys a parachute and the other doesn't ... which one hits the ground first?
     
  15. Anchorsteam

    Anchorsteam TS Member

    Joined:
    Feb 23, 2010
    Messages:
    872
    7mm rifle bullet has better BC than a 30 caliber bullet - with both being roughly equal in shape and weight. The 7mm simply flys better.

    Gravity question - a 22 rifle and and a 300 winmag both barrels set at same angle to the ground and then fired simo. The bullets hit the ground at (about) the same time due to gravity?
     
  16. timb99

    timb99 Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    7,332
    Location:
    Shawnee, Kansas, USA
    <i>"The bullets hit the ground at (about) the same time due to gravity?"</i>

    Yes
     
  17. Tripod

    Tripod Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    2,354
    Location:
    Iowa man!!
    Same time if the barrels were level with the ground plane, but the winmag would have traveled way farther. Drop one at the muzzle and when the fired bullet hits the ground the dropped one will hit at the same time.
     
  18. timb99

    timb99 Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    7,332
    Location:
    Shawnee, Kansas, USA
    Mythbusters actually tested this recently, and when they finally figured out how to release the bullet and shoot the 45 ACP at exactly the same time, the results were that the drop time was within milliseconds of being exact.
     
  19. Hap MecTweaks

    Hap MecTweaks Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    9,229
    Location:
    Mesquite, Nevada
    Tim, I'd wager their measuring equipment/timing was farther off than the actual time it took for both bullets to hit the ground!

    Hap
     
  20. timb99

    timb99 Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    7,332
    Location:
    Shawnee, Kansas, USA
    Hap,

    It was a pretty elaborate setup, and was filmed with high speed, high resolution cameras. They did a pretty good job, in my estimation.

    The biggest stumbling block they had to overcome (not surprisingly) was to get the bullet to drop at <i>exactly</i> the same time as the gun fired.

    I was impressed.
     
Thread Status:
Not open for further replies.