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HELP Assignment due in an hours

  1. Oct 5, 2006 #1
    HELP !!! Assignment due in an hours

    A gold ball is hit from ground @ 25* to the horizontal. When it lands, it has a velocity of 20 m/s @ 30* below horizontal.
    A) find initial speed
    B) time that ball is in air
    C) height of landing pt. relative to start pt, which may be positive or negative
     
  2. jcsd
  3. Oct 5, 2006 #2

    Hootenanny

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  4. Oct 5, 2006 #3
    i've got another one too..
    A motorcycle is stationary at traffic light. At t=0s, light turns green and it accelerates at 3m/s2 when light turns gree, a car is 40 m behind the motorcycle and travelling at 15m/s. At that instant, car slows down at a constant rate so it is never closer than 5 m to motorcyle.
    A) time when car is closest to motorcycle
    B) instant rate of car stopping
    C) distance travelled by motorcycle from light turning green to tim in A)
     
  5. Oct 5, 2006 #4

    Hootenanny

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    RE: See above post.
     
  6. Oct 5, 2006 #5
    1/2at2 - 1/2(1.5)t2 + 15t -35.0 = 0 what do i do from there
     
  7. Oct 5, 2006 #6
    a = (3t-15.0)/t is what i got for a
    Now i need to sub that into above to solve for t
     
  8. Oct 5, 2006 #7
    i suggest setting two equation one for motorcycle and one for the car then combine the two equation 1 = equation 2 and solve for T i believe.
     
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