posted by Kristi
The drawing (which I will describe) shows a top view of a door that is free to rotate about an axis of rotation that is perpendicular to the screen. Find the net torque (magnitude and direction) produced by the forces F1 and F2 about the axis. Picture displays a yellow horizontal line (the door) whose axis is measured at 0.500m from the left side of the door. The larger portion of the door, on the right side of the axis, measures 1.10m. F1 points upward onto the very left edge of the door while F2 points at a diagonal, leaning to the left, but onto the very right edge of the door. This angle that it creates here, with a y-axis dotted line, is 30 degrees. F1 is 20 N while F2 is 35 N.
What you have to do is this:
Sum Vertical forces and set to zero.
This the addition of the weight of the door, plus the two upward components of the F1 and F2.
sum horizontal forces and set to zero.
Now, sum moments about any point (I suggest one of the hinges), and set to zero.
These three equations will solve your system.