Engineering Mechanics Statics Certification Review Exam Questions With Multiple Choices And Verified Answers.

truss - correct answer structure composed of slender members joined together at their end points two-force member - correct answer the force acting at each end of the member will be directed along the axis of the member method of joints - correct answer if an entire truss is in equilibrium, then each of its joints are in equilibirum zero-force member - correct answer Members that support no loading. Used to increase the stability of the truss during construction. method of sections - correct answer if an entire truss is in equilibrium, then any segment of the truss is also in equilibrium multiforce member - correct answer members that are subjected to two of more forces frames - correct answer support loads machines - correct answer contain moving parts and are designed to transmit and alter the effect of forces shear force - correct answer the force component Vb that is tangent to the cross section normal force - correct answer the force component Nb that acts perpendicular to the cross section bending moment - correct answer couple moment Mb torsional moment - correct answer applied torque Mb in three dimensions shear force diagram - correct answer a graph of V versus x of the resulting function of x moment diagram - correct answer a graph of M versus x of the resulting function of x dry friction - correct answer occurs between contacting surfaces of bodies when there is no lubricating fluid coefficient of static friction - correct answer constant of proportionality, "mu sub s" found by dividing frictional force by normal force angle of static friction - correct answer angle "phi sub s" that Rs makes with N coefficient of kinetic friction - correct answer constant of proportionality, "mu sub k" angle of kinetic friction - correct answer angle "phi sub k" that Rk makes with N limiting static frictional force - correct answer maximum value needed to maintain equilibrium five characteristics of dry friction - correct answer 1. the frictional force acts tangent to the contacting surfaces in a direction opposed to the motion or tendency for motion of one surface relative to another 2. the maximum static frictional force Fs that can be developed is independent of the area of contact, provided the normal pressure is not very low nor great enough to severely deform or crush the contacting surfaces of the bodies 3. the maximum static frictional force is generally greater than the kinetic frictional force for any two surfaces of conact. however if one of the bodies is moving with a very low velocity over the surface of another, Fk becomes approximately equal to Fs 4. when slipping at the surface of contact is about to occur, the maximum static frictional force is proportional to the normal force, such that Fs=usN 5. when slipping at the surface of contact is occurring, the kinetic frictional force is proportional to the normal force, such that Fk=ukN three types of frictional forces - correct answer 1. no apparent impending motion: total number of unknowns to be equal to the number of available equilibrium equations 2. impending motion at all points of contact: total number of unknowns to be equal to the number of available equilibrium equations plus total number of available frictional equations 3. impending motion at some point of contact: total number of unknowns will be less than the number of available equilibrium equations plus the number of available frictional equations or conditional equations for tipping wedges - correct answer inclined planes used to increase the application of a force. the two force equilibrium equations are used to relate the forces acting on the wedge screws - correct answer square-threaded screws are used to move heavy loads. they represent an inclined plane, wrapped around a cylinder belts - correct answer the force needed to move a flat belt over a rough curved surface depends only on the angle of belt contact and the coefficient of friction center of gravity - correct answer represents a point where the weight of the body can be considered concentrated center of mass - correct answer coincides with the center of gravity provided the acceleration of gravity is constant coincides with the centroid provided the material is homogenous centroid - correct answer location of the geometric center of the body composite bodies - correct answer a body that is a composite of several shapes moments of inertia - correct answer represents the second moment of the area about an axis parallel axis theorem - correct answer if the moment of inertia for an area is known about a centroidal axis, then its moment of inertia about a parallel axis can be determined radius of gyration - correct answer provided the areas and moments of inertia are known, the radii of gyration are determined from the formula k=root(I/