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Kinematics Problem on a bullet

  1. Jun 28, 2005 #1
    A rifle is aimed horizontally at the centre of a large target 200m away. The initial speed of the bullet is 500 m/s.
    (a) Where does the bullet strike the target?
    (b) To hit the centre of the target, the barrel must be at an angle above the line of sight. Find the angle of elevation of the barrel.

    What does (a) mean actually? And can anyone draw out the diagram ? Thanks.
  2. jcsd
  3. Jun 28, 2005 #2
    Part a. is asking for how far below the centre of the target the bullet hits I think. It's a projectile motion problem.
  4. Jun 28, 2005 #3
    The how to calculate the value? since we just know how far is the target beyond the rifle.
  5. Jun 28, 2005 #4
    (a) If the bullet is aimed directly at the centre of the target and bullet is let out , it will eventually start falling with gravity and will hit a point below the target.Simple projectile motion problem.

  6. Jun 28, 2005 #5
    You can work out the time it takes to travel that distance horizontally, then find the vertical distance travelled in the same time.
  7. Jun 28, 2005 #6
    does it mean displacement in y-compenent is the value this question ask for?
  8. Jun 28, 2005 #7

  9. Jun 28, 2005 #8
    And how to solve the (b) question?
  10. Jun 28, 2005 #9
    So that you donot miss the target , you need to raise your gun up making some angle with horizontal.Calculate that angle.

  11. Jun 28, 2005 #10


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    Science Advisor

    The point is that, in order to do this problem, you should have formulas relating the horizontal and vertical distance to time, initial speed, acceleration due to gravity. What formulas do you have to use?
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