There isnt enough information to answer the question, the missing variable is "distance from said falling spot and ground"
D I think .... don’t be mad if I’m wrong
Answer:
The solved problem is in the photo. Hope it helps.
Answer:
m v1 = (m + M) v2
v2 = m v1 / (m + M)
v2 = 7 * 74 / (74 + 65)
3.73 m/s
74 kg is too heavy for the cannonball (over 150 lbs)