Momentum before collision:
= (Mass of bullet x velocity of bullet) + (Mass of block x velocity of block)
= (4.1 Kg/1000 x V m/s) + ( 0.90 kg x 0)
= Momentum after collision
Momentum after collision:
= (Mass of bullet + Mass of block ) x velocity of bullet
= (4.1 Kg/1000 + 0.90 Kg) 4.0 m/s
= 3.6164 Kg-m/s
Momentum before collision = Momentum after collision
4.1 Kg/1000 x V m/s = 3.6164 Kg-m/s
V = 882.048 m/s