Answer
495N
Work Step by Step
The firefighter weighs 712N, which means that Fg = mg = 712N and the mass of the firefighter is 72.7kg. If there were no pole, the firefighter would accelerate at 9.81 $m/s^2$ since this is the acceleration due to gravity. Since he is only traveling at 3.00$m/s^2$, the pole must be accounting for the additional 9.81-3.00 = 6.81 $m/s^2$. Then since F=ma, we have F = (72.7kg)(6.81 $m/s^2$) = 495N