1-D example, cont.
This is a collision problem, so we have
(1/2)m1v1i2 + (1/2)m2v2i2 =
(1/2)m1v1f2 + (1/2)m2v2f2 + Elost
m1v1i + m2v2i = m1v1f + m2v2f
We know: m1 = 5 grams, m2 = 400 grams, v2i = 0 m/s (wood block is at rest initially), v1f = v2f = 4 m/s (since bullet becomes embedded in block). We are looking for v1i and Elost .