Static Equilibrium

•   Choose one of the two remaining threads and pull on it, varying the force and angle until there seems to be little force on the central pin. Put a third hanger on this thread, run the thread over the third pulley, and add mass to it until the force on the pin seems to be zero.
 
•   Check that the points of the pulleys are aligned with the directions of the threads, and that all of your angles with respect to the long axis of the stick are greater than 15^o.  Remove the pin.  If you have successfully found the conditions for rotational and translational equilibrium, the stick will not move.  Just in case friction between the threads and pulleys might be limiting the stick’s motion, tap on the force table to see if the stick changes its position from the center of the table.  Adjust masses and angles if necessary.
 
•   Repeat the procedures for Questions 2 and 3 for Questions 4 and 5 of the worksheet.  In comparison to the first set of questions, the second set includes a third force (and torque), and you are asked for the sum of the force magnitudes, forces, and relative error in force.  This time, you may place the origin where you choose, but make sure that both the data in the table and the coordinates in the sketch are consistent with your choice.  If you start to run out of time, collect the raw data (yellow cells) and finish your work later.  If any of the fractional error components are greater than 0.099, redo your calculations or repeat the experiment.  Don’t forget to note your units in the square brackets at the top of each column.
 
•  Individually answer the last question about the force of the pin on the stick for the first case, for which you considered only rotational equilibrium.  Think about if translational equilibrium still applies.