A pirate demands that his 75kg prisoner "walk the plank".The prisoner walks out on an 8.0m long,50kg horizontal board that juts out from the side of the pirate ship.If he walks out 7.5m from the place where the board is connected to the ship's side,what is the net torque applied to the board?
A) 5500 Nm
B) 7500Nm
C) 0 Nm
D) 2000 Nm
E) Cannot determine

Question

Quizplus · Accepted Answer

The net torque is 0 Nm because the board is in equilibrium. The torque due to the weight of the prisoner is balanced by the torque due to the weight of the board and any support forces at the connection point.

A Pirate Demands That His 75kg Prisoner "Walk the Plank