Va person carries a plank of wood 2.0 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 cm from the end of the plank with force f2. show answer no attempt 50% part (a) if the plank has a mass of 19.5 kg and its center of gravity is at the middle of the plank, what is the force f2, in newtons?

392N

Explanation:

To develop this problem it is necessary to refer to the equations based on film mechanics. In which the equations of torque and force are defined.

To develop the problem, we assume that when force F_1 is applied, the system is in equilibrium and therefore the net torque is zero.

In this way we can start from the premise that the torque on the pivot is balanced as:

Where m is the mass of the plank and r the distance of center mass. Also represent the distance of force point from end point.

Replacing,

Note that I convert all the measures to International System.

need to see circuit to get time constant

the answer is b, have negligible mass