1. A ruler is initially at rest and horizontal when a student briefly exerts a downward force on the right end. The magnitude of the force exerted by the student is less than the weight of the ruler. a. Pivot (Assume that the pivot is frictionless.) Ruler Describe the rotational motion of the ruler: Describe the translational motion of the ruler (ie, the motion of its center of mass): a. i. while the hand is pushing, and i. while the hand is pushing, and ii. at an instant after the hand has stopped pushing. ii. at an instant after the hand has stopped pushing. b. Draw an extended free- body diagram for the ruler at an instant: i. Free-body diagram for ruler while hand is pushing ii. Free-body diagram for ruler after hand has stopped pushing i. while the hand is pushing, and ww.w. ii. after the hand has stopped pushing. c. Rank the magnitudes of all the forces on your diagrams in order, from largest to smallest. Tutorials in tetroductory Physies McDermott, Shaffer, & P.E.G., U. Wash. CPrentice Hall, Inc. First Edition, 2002 f. Check that your descriptions of the motion of the ruler in part a are consistent with your counterclockwise sense, Mech Dymamics of rigid bodies HW-68 or zero at cach of the two instants shown? Explain. After hand has stopped pushing e. In the boxes at right, indicate the direction of the net force on the ruler at each of the two instants in part b. If the net force is zero, state that explicitly. Explain. While hand is pushing List all of the forces on each of your free-body diagrams that must be summed to obtain the net force. Explain. answers in parts d and e.