Answer
The tension in the cable is $929.3N$.
Work Step by Step
The tension in the cable $T$ is the force that pulls the stuntman and is directed in the direction of motion of the truck. Opposing this force is the kinetic frictional force $f_k$.
The free-body diagram is drawn below.
Since the stuntman is pulled at a constant velocity, these two forces cancel each other out. In other words, $$T=f_k=\mu_k F_N$$
The normal force $F_N$ can be calculated to be equal with $mg$, as the normal force and the weight cancel each other too. $$T=\mu_kmg=0.87\times109\times9.8=929.3N$$
