an 83.2 kg girl is standing on a frictionless ice surface through a 2.00 kg book at 12.6 m/s at what velocity does the girl move across the ice?

Answer 1

conservation of momentum

m1u1+m2u2=m1v1+m2v2

m1 = mass of first thing (girl)
m2 = mass of second thing (book)
u1 = initial velocity of first thing (girl)
u2 = initial velocity of second thing (book)
v1 = final velocity of first thing (girl)
v2 = final velocity of second thing (book)

if the book and girl both start at rest (0 m/s) see if you can find v1 now.