The net force is 12 N to the left.
<span>The initial momentum of the boy is equal to the boy/boat because the final velocity of the boat is less than the initial velocity of the boy.</span>
By applying Newton's second law of motion;
ma = mg - T
Where,
m = mass; a = downward accelerations (+ve value) or upward acceleration (-ve value); g = gravitational acceleration; T = tension.
For the current case, the velocity is constant therefore,
a = 0
Then,
0 = mg - T
T = mg = 115*9.81 = 1128.15 N
Tension in the cable is 1128.15 N.
