1. An experimental device imparts a force of magnitude F = 225 N to the front edge of the rim at A to simulate the effect of a slam dunk.

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2 1. An experimental device imparts a force of magnitude F = 225 N to the front edge of the rim at A to simulate the effect of a slam dunk. Determine the moments of the force F about point and about point B. Finally, locate, from the base at, a point C on the ground where the force imparts zero moment. (2/35)

3 F = 225 N, =?, B =?, locate, from the base at, a point C on the ground where the force imparts zero moment. F y F 135 N x F 180 N y N m ( ccw) F x B B N m ( cw)

4 F = 225 N, =?, B =?, locate, from the base at, a point C on the ground where the force imparts zero moment. F y C d d d m d mm 0 F x d 1600mm C

5 2. A prybar is used to remove a nail as shown. Determine the moment of the 240 N force about the point of contact between the prybar and the small support block.

6 ? 240cos N sin N ( clockwise direction ) 0.35 N m

7 3. Calculate the moment of the 250 N force on the handle of the monkey wrench about the center of the bolt. (2/35)

8 ? 250cos N 250sin N Nm ( cw)

9 4. Calculate the moment o of the 250 N force about the base point of the robot.

10 250cos50? sin 50 d y d x + 250cos cos600.3cos50 250sin sin 600.3sin N m ( ccw)

11 5. The 120 N force is applied as shown to one end of the curved wrench. If a = 30, calculate the moment of F about the center of the bolt. Determine the value of a which would maximize the moment about ; state the value of this maximum moment. (2/54)

12 N m F = 120 N, a = 30, =? a =? for max. Compute max sin cos30 ( cw) cosa sin a a=40 120cosa F y 22.8sin a 34.8cosa F x 120sina d 22.8cosa 34.8sin a 0 da sin a tana cosa 34.8 a max N m ( cw)

13 6. The spring loaded follower A bears against the circular portion of the cam until the lobe of the cam lifts the plunger. The force required to lift the plunger is proportional to its vertical movement h from its lowest position. For design purposes, determine the angle q for which the moment of the contact force on the cam about the bearing at is a maximum. (2/53) In the exploded view of the contact, neglect the small distance between the actual contact point B and the end C of the lobe.

14 The force required to lift the plunger is proportional to its vertical movement h from its lowest position. Determine the angle q for which the moment of the contact force on the cam about the bearing at is a maximum.

15 7. The small crane is mounted along the side of a pickup bed and facilitates the handling of heavy loads. When the boom elevation angle is q = 40 o, the force in the hydraulic cylinder BC is 4.5 kn, and this force applied at point C is in the direction from B to C (the cylinder is in compression). Determine the moment of this 4.5 kn force about the boom pivot point. (2/57)

16 when q = 40 o, F BC =4.5 kn (directed from B to C)?

17 8. Assume that the hydraulic cylinder AB exerts a force of constant magnitude 2.5 kn as the bin is elevated. Determine the moment of F about the point as a function of q for the range 0 q 90 o. At what angle q is this moment a maximum and what is the maximum moment? F

18 F AB =2.5 kn, f(q) =? (0 q 90 o ). q? for max. Compute max.

19 9. The pipe assembly is subjected to an 80 N force. Determine the moment of this force about point A.

20 F x Fy F z? A m N k j i i j i k j k k j i k j i mm C A F r A A A A C A ,400, 0,0,0 / N k j i F z N F N F N F z y x ) ( 40 80sin cos30cos cos30sin 40 m N A

21 10. A 300 N force is applied to the handle of the winch as shown. The force lies in a plane which is parallel to the y-z plane and is perpendicular to the line AB of the handle. Determine the moments of this force about point and about the x-axis. (2/133)

22 The force lies in a plane which is parallel to the y-z plane and is perpendicular to the line AB of the handle. Determine the moments of this force about point and about the x-axis. F 300sin 60 j 300cos60k j 150k N F y 0,0,0 A 115,350cos40,350sin 40 A 115, , mm r A / F z r A / F x i N m 29.87k j 40.2i 58.46i 98.66i j 29.87k Nm i j 0.225k j 150k x 98.66i Nm

23 11. A 5 N vertical force is applied to the knob of the window-opener mechanism when the crank BC is horizontal. Determine the moment of the force about point A and about line AB. (2/144)

24 Determine the moment of the 5 N force about point A and about line AB. A0,0,0m, D 50cos3025cos30, 75,50sin 30 25sin 3065, 75,37.5 B 50cos30, 0,50sin , 0, 25mm F 5k, rd / A 65i 75 j 37.5k A rd / A F 325 j 375i ( N mm) A 65i 75 j 37.5k 5k ( mm) mm n AB or AB AB AB 43.3i 25k 0.866i 0.5k nab cos30i sin 30k 0.866i 0.5k A nab ( 375)(0.866) n i 0.5k AB AB i k ( N mm) ( N mm)

25 12. In opening a door which is equipped with a heavy-duty return mechanism, a person exerts a force P of magnitude 32 N as shown. Force P and the normal n to the face of the door lie in a vertical plane. Compute the moment of P about the z axis. (2/129)

26 P=32 N, compute the moment of P about the z axis.

27 13. The arms AB and BC of a desk lamp lie in a vertical plane that forms an angle of 30 o with xy plane. To reposition the light, a force of magnitude 8 N is applied as shown. Determine, a) the moment of the force about point A, b) the moment of the force about the axis of arm AB, c) The angle between AB and the force, d) The perpendicular distance between AB and the line of action of the force. 8 N Direction CD is parallel to the z-axis and lies in a parallel plane to the horizontal plane. AB 450 mm, BC 325 mm

28 a) A b) AB c) q, between AB and F d) d, dis tan ce between AB and F AB450mm BC 325 mm 8 N

29 100 mm P y B f C 200 mm z 150 mm q A x 14. Concentrated force P is acting perpendicular to the crank arm BC at point C. For the position q =70, what is x, the moment of about the x axis? At this instant, y =-20 N m and z =-37.5 N m.

30 q=70, x =?, when y =-20 N m and z =-37.5 N m. 100 mm P y B f C 200 mm z 150 mm q A x