A person is carrying a plank of wood 2.00 m long with one hand pushing down on it at one end
with a force F1 and the other hand holding it up at 50.0 cm from the same end of the plank with
force F2. If the plank has a mass of 20.0 kg and its center of gravity is at the middle of the plank,
what are the forces F1 and F2?