Momentum
mava + mbvb = mava '+ mbvb'
(300 x 10)+(150 x 0) = (300 x 4.12)+(150 x vb')
3000=1236+150vb'
1764 = 150vb'
vb'=+11.76 m/s ≈ +11.8 m/s (positive sign, to the right)
