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Finding Final Velocity by Energy Techniques

  1. Oct 13, 2004 #1
    A 1.50 kg snowball is fired from a cliff 13.5 m high with an initial velocity of 14.0 m/s, directed 41.0° above the horizontal.
    (a) Using energy techniques, rather than techniques of Chapter 4, find the speed of the snowball as it reaches the ground below the cliff.
    ok so I used the equation k1+u1=k2=u2
    plugging in numbers i did 1/2(1.50kg)(14m/s)^2+(1.50kg)(9.8m/s^2)(13.5m)=1/2(1.50kg)(vf)^2+(1.50kg)(9.8m/s)(0). Then I solve for Vf and I get a wrong answer. Now i realize this is probably wrong since I haven't incorporated the angle, but I'm not sure. Any ideas?
     
  2. jcsd
  3. Oct 13, 2004 #2

    Galileo

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    Well. The technique is right, so you must've made some silly error in solving for Vf.
    What answer did you get? It should be 21.5 m/s.
     
  4. Oct 13, 2004 #3
    Yeah 21.5 is the answer, guess I must have made a mistake with the calculator :blushing: . Thank You :smile:
     
  5. Oct 13, 2004 #4
    Hey GingerBread27 please check your private messages...thanks!
     
  6. Oct 13, 2004 #5
    GingerBread27 check your private messages 1 more time...thanks
     
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