Mass attached to a long bar

For this demonstration experiment I need a strong person. The object will be to keep a steel rod from rotating. You hold on to a perpendicular steel handle welded to the other end of the rod. The rod is not very heavy but if I attach a mass a one end the force of gravity acting on it produces a torque which you must counteract by clutching to the handle thus producing a frictional torque. We note that

• The larger the mass the larger torque
• The larger the moment arm the larger the torque
• When we raise the rod towards the vertical position torque produced by gravity is reduced. This is because less of the fixed gravitational force contributes to the tangential component. Another way to look at it is to notice that
  
  is the total force of gravity multiplied by the perpendicular distance from the line of force to the axis of rotation.