7. Two men exert forces of F = 80 lb and P = 50 lb on the ropes. (a) Determine the moment of each force about A. (b) Which way will the pole rotate, clockwise or counterclockwise? 6ft 12 ft

52 Chapter 2 Force Systems 2/57 When making a left turn, a driver exerts two 1.5-lb forces on a steering wheel as shown. Determine the moment associated with these forces. Discuss the ef- fects of varying the steering-wheel diameter d. Ans. M 24 lb-in. CCW 1.5 lb 35° Ans a 1.5 lb d = 16"

3. The hinged door shown has a chain attached at point C connected to point B. It has a tension force of 250 N. To maintain the door in that position shown, what is the magnitude of the moment of the axis where the hinges are attached? 2.5 m 1.5 m Fc = 250 N. 30 1 m 0.5 m

A man exerts a force F on the handle of the stationary wheelbarrow at A. The weight of the wheelbarrow along with its load of dirt is 200 lb with center of gravity at G. For the configuration shown, what force F must the man apply at A to make the net moment about the tire contact point B equal zero? Express your answer in units of lb. 60° 26" F ***** A 20° 37" W G 8"- B

QUESTION 3 For the system of co-planer forces shown, (a) the resultant force and (b) the moment of the resultant force about point O are respectively: (Note: The coordinates of the points are given in metres). (4,3) 28 12 kN 14 kN 120 (4.3,-2.9) component O a. 18.44 kN, 45.46 kNm (counter-clockwise) O b. 18.44 kN, 22.49 kNm (clockwise) O c. 7.42 kN, 132.61 kNm (counter-clockwise) Od.7.42 kN, 22.49 kNm (clockwise)