Kinetic energy transfer problem

[Port]

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 energy transfer is can someone please help!

 

[Sirus]

Transferred kinetic energy is that which is gained by the coin that was initially at rest. Therefore, you can use

E_{K}=\frac{1}{2}mv^2

to find the final kinetic energy of that coin, which, since initial E_{K}=0, is the transferred E_{K}.

 

[Port]

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?

 

[Sirus]

Take a look at your units...

 

[hornytoad57]

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?