Answer:
The tension in the string is 16.24 N
Step-by-step explanation:
Given;
mass of the sphere, m = 1.55 kg
initial velocity of the sphere, u = 2.81 m/s
final velocity of the sphere, v = 4.60 m/s
duration of change in the velocity, Δt = 2.64 s
The tension of the string is calculated as follows;

T = 1.55(0.678 + 9.8)
T = 1.55(10.478)
T = 16.24 N
Therefore, the tension in the string is 16.24 N