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Projectiles in air

  1. Jan 26, 2015 #1
    Is it theoretically possible to get a round bullet to rise if shot horizontally provided the bullet ( projectile) is given "under spin"?
     
  2. jcsd
  3. Jan 26, 2015 #2

    berkeman

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    Staff: Mentor

    That's more of a golf ball dimple backspin type question, isn't it? :)
     
  4. Jan 26, 2015 #3
    How about a round hollow bullet made of some light alloy and dimpled then? But shot from a rifle giving it underspin.

    Could it be done?
     
  5. Jan 26, 2015 #4
    Could it, anywhere in its flight, get higher than the vertical height it was shot at, even if just for a moment and barely higher?
     
  6. Jan 26, 2015 #5

    berkeman

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    Staff: Mentor

    What does the literature say about backspin for dimpled golf balls? Does it produce lift? Enough lift to just partially retard normal gravitational drop, or enough to actually cause the ball to rise? How can you extend that to your question?
     
  7. Jan 26, 2015 #6

    berkeman

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    Staff: Mentor

    Also,, have you read about the new smart rounds? They can alter their path in flight....
     
  8. Jan 26, 2015 #7
    I have accomplished this with a ping pong ball. Striking it with a rat trap lifting off a horizontal table. I hit the ball below the center of course.
    I have a friend who says it's impossible. I say it's possible with air, that he is thinking of the bullet dropped from the same height it was shot at horizontally hitting the ground at the same time, flat Earth, air resistance and lift be damned.

    So I said yes because I've done it. He says no way.
     
  9. Jan 26, 2015 #8
    Done it with a ping pong ball that is.
     
  10. Jan 26, 2015 #9
    Read about the smart bullets.

    I am going to assume if they can change directions (guided) that the certainly could go up for a short distance.
    It must involve in shape thus a change in air flow if the can guide a projectile? I'm guessing?
     
  11. Jan 27, 2015 #10

    cjl

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    Sure, it's absolutely possible. A spinning sphere or cylinder produces an aerodynamic force perpendicular to the travel direction, which could cause it to rise (if the force is larger than the weight of the projectile). It would be difficult to achieve with a bullet due to the high density, but it would be pretty easy with a ping pong ball.
     
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