A 0.132kg baseball is dropped from rest. If the magnitude of the baseball's momentum is 0.811kg m/s just before it lands on the ground, from what height was it dropped?
Calculate velocity from momentum.
Then, knowing velocity at impact calculate height from v^2 = 2gh
1 answer

There's many ways todo this problem. First you solve for Vf b/c we are given that Vi = 0 (at rest). The easiest way is to find Vf (Use momentum equation P = M*V) then just use PE = Mgh ... PE turns into KE as it falls. (KE = 1/2 mv^2 = Mgh) You can solve h from there. Not going todo it for you. Another way todo this problem is find Vf then used 1D kinematics to solve for t and then after given t you can find Delta x from there (Delta x = Vi + vf / 2) * t)