So basically I have a homework question that says:
Block 1 (m1, Vo) hits block 2 (m2, Vf) at rest. Block 1 rebounds at Vf1, and block 2 moves forward at a speed not given.
So m1, Vo, m2, and Vf1 are given, but Vf2 must be calculated. My question is how is it that in the end energy is lost?
Final equation: delta KE= (m1•Vf1^2/2+m2•Vf2^2/2)-m1•Vo^2/2
And Vf2=(m1•Vo-m1•Vf)/m2
So if all numbers are calculated why is there energy loss?
In: 0
There isn’t any energy loss. It’s conserved. There is a *kinetic* energy loss because, in most collisions, there’s heat, sound, and (often) distortion of the colliding objects. The energy changed forms to some that aren’t kinetic, so naturally you’ve got less kinetic energy after than before.
Your second equation (Vf2=…) is just conservation of momentum. This doesn’t looks like it’s an energy question.
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