Support Reactions of a Trapezoidal Slab with Three Points of Support Jhun Vert Sun, 04/19/2020 - 11:26 am

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.
 

eq-parallel-forces-trapezoid-slab.gif
  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 | Equilibrium of Parallel Force System Jhun Vert Sun, 04/19/2020 - 11:19 am

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.
 

Twenty tonner traveling crane

 

Problem 340 - 341 | Equilibrium of Parallel Force System Jhun Vert Sun, 04/19/2020 - 11:10 am

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.
 

System of Five Pulleys

 

Problem 339 | Equilibrium of Parallel Force System

Problem 339
The differential chain hoist shown in Fig. P-339 consists of two concentric pulleys rigidly fastened together.
 

Differential Chain Hoist

 

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.