parallel forces

Situation
A reinforced concrete slab in the shape of an isosceles trapezoid weighs 3600 N/m². It is supported on the three points as shown in the figure.
 

1. Find the reaction at A.
   A.   16,848 N
   B.   6,716 N
   C.   13,372 N
   D.   2,010 N
2. Find the reaction at B.
   A.   16,848 N
   B.   6,716 N
   C.   13,372 N
   D.   2,010 N
3. Find the reaction at C.
   A.   16,848 N
   B.   6,716 N
   C.   13,372 N
   D.   2,010 N

Problem 343
The weight W of a traveling crane is 20 tons acting as shown in Fig. P-343. To prevent the crane from tipping to the right when carrying a load P of 20 tons, a counterweight Q is used. Determine the value and position of Q so that the crane will remain in equilibrium both when the maximum load P is applied and when the load P is removed.
 

Problem 342
The wheel loads on a jeep are given in Fig. P-342. Determine the distance x so that the reaction of the beam at A is twice as great as the reaction at B.
 

Problem 340
For the system of pulleys shown in Fig. P-340, determine the ratio of W to P to maintain equilibrium. Neglect axle friction and the weights of the pulleys.
 

Problem 339
The differential chain hoist shown in Fig. P-339 consists of two concentric pulleys rigidly fastened together. The pulleys form two sprockets for an endless chain looped over them in two loops. In one loop is mounted a movable pulley supporting a load W. Neglecting friction, determine the maximum load W that can just be raised by a pull P supplied as shown.
 

Problem 338
The two 12-ft beams shown in Fig. 3-16 are to be moved horizontally with respect to each other and load P shifted to a new position on CD so that all three reactions are equal. How far apart will R₂ and R₃ then be? How far will P be from D?
 

Problem 337
The upper beam in Fig. P-337 is supported at D and a roller at C which separates the upper and lower beams. Determine the values of the reactions at A, B, C, and D. Neglect the weight of the beams.
 

Problem 336
The cantilever beam shown in Fig. P-336 is built into a wall 2 ft thick so that it rests against points A and B. The beam is 12 ft long and weighs 100 lb per ft.
 

Problem 335
The roof truss in Fig. P-335 is supported by a roller at A and a hinge at B. Find the values of the reactions.