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Homework Help: Kinetic energy transfer problem

  1. Jan 20, 2005 #1
    ok i have a problem with a 0.005kg coin that has an initial velocity of 25cm/s that hits a 0.015kg coin that is at rest. atfer the collision the 0.005kg coin has a velocity of -12.5cm/s. What i have to find is the Kinetic energy transferred was. i got the final velocity for the 0.015kg coin which is 12.5cm/s but i don't know how to figure out the amt of kinetic enegy transfer is can someone plz help!
  2. jcsd
  3. Jan 20, 2005 #2
    Transferred kinetic energy is that which is gained by the coin that was initially at rest. Therefore, you can use


    to find the final kinetic energy of that coin, which, since initial [itex]E_{K}=0[/itex], is the transferred [itex]E_{K}[/itex].
    Last edited: Jan 20, 2005
  4. Jan 20, 2005 #3
    but when i do that i get 1.172 for an answer but it says in my book that the answer is 1.1x10^-4J???
  5. Jan 20, 2005 #4
    Take a look at your units...
  6. Jul 9, 2010 #5
    I have an 8lb sledge hammer, traveling 50 mph hitting an immovable object. The energy created is Ek = 1/2 mv^2. Is the energy transfer to the immovable object the same amount?
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