For a Excelent Applied Statics Tutor: Regards, I need help, because I have to pr
ID: 1661370 • Letter: F
Question
For a Excelent Applied Statics Tutor:
Regards,
I need help, because I have to prepare for a final exam of applied statics (engineering), I have many problems, I went wrong in two exams. The book I am using is Engineering Mechanics Statics by Hibbeler (13th edition). The topics are: Force Vectors, Equilibrium of a Particle, Force System Results, Equilibrium of a Rigid Body, Structural Analysys (Trusses and so on), Center of gravity and centroid (this I understand), moments of inertia (this I also understand it) ). What brings me problems is that I do not know when to apply moments, it confuses me because sometimes I see that they use summations, other times they use position vectors ... others apply summation of forces. I'm well lost from when to apply them. If you could give me an excellent review on that particular topic and how to apply them in the aforementioned topics, I would be very grateful. I would like to do well in the exam, even if I study the book I do not understand. Thanks a lot!
Explanation / Answer
There is always more than one way a given statics problem can be solved: vector approach or scalar approach
In vector approach, the forces and moments are determined vectorially using position vectors and vector multiplications. After this the equilibrium equations are obtained and solved to determine unknown forces.
In scalar approach, the forces and moments are determined using scalar method. In this method one has to be careful about the direction and sign of forces and moments. One has to assume sign convention for positive and negative forces and moments and then develop equilibrium equations acoordingly to solve for the unknows.