Mass of the object, m_{1 }= 1 kg

Velocity of the object before collision, v_{1} = 10 m/s

Mass of the stationary wooden block, m_{2} = 5 kg

Velocity of the wooden block before collision, v_{2} = 0 m/s

∴ Total momentum before collision = m_{1} v_{1} + m_{2} v_{2 }

= 1 (10) + 5 (0) = 10 kg m s^{- 1}

It is given that after collision, the object and the wooden block stick together.

Total mass of the combined system = m1 + m2

Velocity of the combined object = v

According to the law of conservation of momentum:

Total momentum before collision = Total momentum after collision

m_{1 }v_{1}+ m_{2} v_{2} = (m_{1}+ m_{2}) v

v = 10 / 6 = 5 / 3 m/s

The total momentum after collision = 10 and velocity of combined object is 5/3 m/s.