You need to remember the formula of momentum such that:

`p = m*v`

You should use the kinematic equation that helps you to find the velocity such that:

`v^2 = v_0^2 + 2a*x`

Since the initial velocity is zero,the acceleration is g and h represents the height the ball is dropped, you need to substitute these values in the kinematic equation above such that:

`v^2 = 2g*h =gt v = sqrt(2gh)`

Substituting `sqrt(2gh)`  for v in equation of momentum yields:

`p = m*sqrt(2gh)`

`p = 0.1*sqrt(2*9.8*12) =gt p = 1.533 kg*m/s`

Hence, evaluating the momentum when the ball strikes the ground yields  `p = 1.533 kg*m/s` .