Posted by Kelly on Tuesday, April 27, 2010 at 10:52pm.
The collision between a hammer and a nail can be considered to be approximately elastic. Estimate the kinetic energy acquired by a 13 g nail when it is struck by a 550 g hammer moving with an initial speed of 4.0 m/s.
I solved for the final velocities of both and got 3.8 m/s for the nail and 8.46 m/s for the nail.
How do I get my final answer.. I'm so close! haha

Physics  Kelly, Tuesday, April 27, 2010 at 10:54pm
3.8 m/s for the hammer*

Physics  drwls, Wednesday, April 28, 2010 at 2:08am
Assuming that you have the correct velocity for the nail after it is hit (8.46 m/s), call that V and compute its kinetic energy with the usual formula,
KE = (1/2) M V^2
They only want the K.E. of the nail.