(Solved): 6-86. A 300-kg counterweight, with center of mass at \( G \), is mounted on the pitman crank \( A ...

6-86. A 300-kg counterweight, with center of mass at \( G \), is mounted on the pitman crank \( A B \) of the oil-pumping unit. If a force of \( F=5 \mathrm{kN} \) is to be developed in the fixed cable attached to the end of the walking beam \( D E F \), determine the torque \( \mathrm{M} \) that must be supplied by the motor. Prob. 6-86