6-38.Determine the force developed in members GB and G F of the bridge truss and state if these membel-s are in tension or compression. 6-69. The link is used to hold the rod in place. Determine th.e/required axial force on the screw at E if the largest force _to be exerted on the rod at B, C, D is to be 100 N. Also, or find the magnitude of the force reaction at pin A. Assume all surfaces of contact are smooth. , . . 5 ' 'k -./ - : 6-73. The truck exerts the three forces shown on the --+irders of the bridge. The oirders are connected together by a short vertical link DC. Determine the reactions at the supports when the truck is in the position shown. 2 88 . 6 . . determiile the magnitude of the ressltailt force on the pin at A. If Porce of 500 N on the block. STRUCTURAL ANALYSIS block is held in place using the vice clamp. Cll. Determine the horizontal and vertical components of force at C which member ABC exerts on member CEF.6-78. ~. 1 6 ft W--3 ft- 1 300 lb .-/ -. V. Operation of exhaust and intake valves in an automobile engine consists of the cam C. push rod DE. The spring has a stiffness of 300 N/m. If the compression in the spring is 20 mm when the valve is open as shown: determine the normal force acting on the cam lobe at C. I. rocker arm EFG which is pinned at F?and a spring and valve. and J are smooth. .:::6-80. Assume the cam and bearings at H. Determine the horizontal and vertical components of reaction at the pins A and D. Also.6-83. The wall crane supports a load of 700 lb. what is the force in the cable at the winch W? . srtson beam AB.Determine the force that the smooth roller C -.. :i:6-84. . what are the horizontal and vertical components of reaction at pin A ? Neglect the weight of the frame and roller. Also.-ex. .--derrick the maximum force that can be sustained if by the pin at A is 18 kN. Determine the largest mass that can be supported by -*-the.:"6-92. The derrick is pin-connected to the pivot at A. .Determine the required mass of the suspended cylinder if the tension in the chain wrapped around the "Yi-eelgturning gear is to be 2 kN. what is the magnitude of the resultant force on pin A ? *I 6-93. Also. orce exerted or. the 500-1S stone st F and C I order to lift it. 1 ft-71 ftL . Determine the horizontai and vertical ~mponents f f o. .tongs consist o two jaws pianed to links at f d D. If the force which the plate exerts on the head is P = 12 kN? determine the force F in the hydraulic cylinder when 8 = 30'. pressing the plate p into the cavity. The toggles push the movable bar G forward. . which are operated by the hydraulic cylinder H.6-97. It consists of two toggles ABC and DEF. The machine shown is used for forming metal plates. D E . symmetrically located on ecich side of the platform. The scissors lift consists of two sets of cross members and two hydraulic cylinders. Deternline the force in each of the hydraulic cylinders for equilibrium. The load of 85 kg. with center of gravity at G?. . Rollers are located at B and D. is centrally located between each side of the platform. with a center of gravity at GI.Prabt~. The platform has a uniform =ass of 60 kg. 6-97 b&3--9t 6-98. / i L? b The clamp is used the smooth strut S in place.determine the force exerted at points A and B..t j r pi< . If ie force in the bolt GH is 300 N. . The bucket of the backhoe and its conte:~tshave a weight of 1200 lb and a center of gravity a t G.6-102. The bucket is pinned at E. . Deternine the forces of the hydraulic cylinder AB and in links AC and AD in order to hold the load in the position shown. .pillar crane is subj ected to the loaa av11-1 kg. Determine the force developed the rod AB and rile hol-izontal and vel-tical reacrions at the pir. Support C when tile boom is tied in the position shown. -. 1 0 The symmetric coil tong supports the coil which 6has a mass of SO0 kg and center of mass at G. Determine the horizontal and vertical components of force the linkage exerts on plate DEIJH at points D and E. The coil exerts only vertical reactions at K and L.-- :\--. . ! '.m i n e the compressive force deve. 6-107. /' .loped on the smooth bolt shank A at the jaws.) A 5-lb force is applied to the handles of the vise M e t e l . '-1.75 in. 0. 10 lb . d etermine the compressive force F tha t the block exerts on the clamp.5 in.orip of the If a force of 10 lb is applied to the a clamp.5 in.+-] I 8. in equilibrium. The shovel load has a mass of 1.6-111.25 Mo and a 5 center of gravitv at G. . 2 - .<:'Determine the force created in the hydraulic .-qdinders EF and AD in order to hold the shovel . All joints are pin connected. h has a center of mass at G.\a%.> The tractor Soom supports the uniform Inass of # 500 kg in the bucket whic. The load is supported equally 01-1 each side of the tractor by a similar mechanism. . Determine the force in each hjrdraulic cylinder A B and CD and the resultant force at pins E and F. 2 in. . T l ~ episton at N has a crosssectional area of A = 2 in2. Hill/: First find the force F acting a l o n ~ . I F the load oil the jack is 2000 lb./PB The linkage fol.1 . determine the PI-essure acting on the fluid when the jack is in the positioil shown. link L . EN. The pressuse in the fluid is p = FIR.a hydi-aulic jack is shown. All lettered points are pins. 2 in. -- . Determine the force in the hj7draulic cylinder AB and the force in links AC and A D when the load is held in the p6sition shown.6-122. . The hydraulic crane is used to lift the 1400-lb load.