Question

Part A
Which of these bodies has redundant constraints for the given loading conditions? F1 and F2 are applied, known forces. In the first choice, the support at A is fixed and a cable connects points B and C. In the second choice, the support at A is a smooth pin, and a cable connects points B and C. In the third choice, the support at A is a single thrust bearing, and a cable connects points B and C. In the fourth choice, the supports at A and B are hinges, and the support at C is a roller.
Check all that apply.

	Which of these bodies has redundant constraints for the given loading conditions? F1 and F2 are applied, known forces. In the first choice, the support at A is fixed and a cable connects points B and C. In the second choice, the support at A is a smooth pin, and a cable connects points B and C. In the third choice, the support at A is a single thrust bearing, and a cable connects points B and C. In the fourth choice, the supports at A and B are hinges, and the support at C is a roller. Which of these bodies is improperly constrained?

Part B

Which of these bodies is improperly constrained?

Check all that apply.

Check all that apply.

Answer 1

Part A Free body diagram of rod AB The unknowns are two set of reactions at A and fixed moment a A. tension in the string BC so a total 4 unknowns The basic set of equations for equilibrium are, There are 4 unknowns and 3 equati ons so bar AB under Free body diagr am of rod AB. The unknowns are two set of reactions at A and tension in the string BC so a total 3 unsAA.&T The basic set of equations for equilibrium are, There are 3 unknowns and 3 equati ons so bar AB under normal constrain (ie non redundant) Choice 3. Free body diagr am of rod AB d/2 The unknowns are twopoints two reactions at A and direction of tension in the string BC is lso unknowns. 5 unkwns The basic set of equations for equilibtiam are, There are 3 unknowns amd 6 equations Conly 3 me required) so bar AB under normal constrain (i.e non redhndnt) Choice 4 Free body diagram of AB. If suppost at Cis removed, the feasibility of the entie system will aot change. Hence it is redundant constraint Part B Free body diagram of rod AB There are forces in both x and y direction but the constraint in X and y direction Therefere, the body is properly constrained Choice 2 Free body diagram of rod AB There are fcrces in both x and y direction but the constraint is only in the y direction. Therefore, the bodyis impeoperly constrained. Free body diagram of rod AB There are forces in both x. y and z direction and constraints are only all three x, y and z direction. In addition the block is not allowed to have any rotational moment due to shaft and chord. So the body is properly constrained Free body dagram of rod AB There are forces in both x·y and z direction and constraints are only n all three x, y and z direction. But the moment caused by the (F, xd) is not constrained So the body is improperly constrained.