20) For this problem, we know of two masses on opposite sides of a plank on a pivot point. Initially, the system is in static equilibrium, which means the net torque is 0.
Now that we know their masses relative to each other, let's see what happens to the torque if both objects are moved 2 meters towards the center pivot.
We will start this process by looking at the force diagram.
From this point, we can look at the net torque. As usual, we will take counterclockwise as the positive direction and clockwise as negative.
Torque is like the angular equivalent of a force, and just like an acceleration is produced by a net force, an angular acceleration is produced by a net torque.
Remember that we defined counterclockwise to be the positive direction. Our net torque is positive, so we know the plank angularly accelerates until the left side reaches the ground.
Answer: E
Comments