A person carries a plank of wood 1.6 m long with one hand pushing down on it at one end with a force F1 and the other hand holding it up at 43 cm from the end of the plank with force F2. If the plank has a mass of 13.7 kg and its center of gravity is at the middle of the plank, what is the force F1

Explanation:

Given

Length of plank is 1.6 m

Force is applied on the left side of plank

Force is applied 43 cm from the left end O.

Mass of the plank is

for equilibrium

Net torque must be zero. Taking torque about left side of the plank

Net vertical force must be zero on the plank

it becomes positively charged by charging it