Answer:
3,6 m/s
Explanation:
You need to calculate the force with which the man jumps, and since
Force = Mass * Speed, here's what you have:
Force = 8,84 * 51,6
Force = 456,144 N
Then, you would have to apply the same formula, but this time to find the speed of the boat, using the force:
456,144 = x * 126,6
x =~ 3,6 m/s