Engineering Mechanics 151-200 Flashcards
- It is the intensity of the force.
Magnitude
- Sense and slope of angles with respect to reference axes
Direction
- The resultant of two forces which is the diagonal formed on the vectors of this force.
Parallelogram law
- Any pressure on the support causes an equal and opposite pressure from the support.
Action and reaction
- Two forces on a rigid body will in no way to be changed if we added or subtract from them another system of forces in equilibrium.
Superposition law
- Quantities which possess magnitude.
Scalar quantities
157 Quantities having both magnitude and direction.
Vector quantities
- Quantities which possess magnitude but require two or more directional aspects.
tensors
- When several forces act in a given situation.
System of forces
- All forces of the system are in a common line action.
collinear forces system
- The action line of all the forces are in the same plane and intersect a common point
concurrent, coplanar
162.The action line of all the forces of the system are parallel and lie in the same plane
parallel, coplanar
- The action line of all the forces of the system are in the same plane, but they are not parallel and don’t intersect in a common point.
non concurren, coplanar
- The action line of all the force are not in the same plane and intersect a common point.
concurrent, non-coplanar
- The action lines of all the forces of the system are parallel and not all lie in the same plane.
Parallel, non-coplanar
- The action lines of all forces of the system are all not in the same plane but they are all not parallel do not intersect in a common point.
non concurrent, non-coplanar, non-parallel
- The simplest force system that can replace the original system without changing its external effect.
Resultant
- A pair of parallel forces having same magnitude bur opposite senses.
Couple
- The process of replacing a force system by its resultant
composition
- A pictorial respresentation in solving a system
Graphical
- Is used to obatin the magnitude and direction of the resultant of any two concurrent forces.
Triangle law
- An analytical method of finding the resultant of concurrent forces.
Resolution
- Means that either one of two coplanar forces having the given force as resultant.
components
- Is used to check the results obtained from the resoltuion and composition methods.
Polygon method
- Its is a vector quantity that is represented as a vector along the moment axis.
Moment of force
- The algebraic sum of the moment of its forces about any axis perpendiculat to the plane of the couple.
The moment of the couple.
- The force of attraction of the earth on a body
Weight
- Theorem of pappus which state that the surface area of any solid of revolution is the product of the length multiplied by the distance travelled.
1st proposition
- The volume of any solid of revolution is the product of the generation area
2nd proposition
181 Theorem used in locating the centroid of the semicircle arc.
Pythagorean theorem; Newton’s theorem; Pappus theorem
none of the above
- A system of forces acting on a body which has no resultant.
Equilibrium
- A system of forces acting on a body which has no resultant.
Equilibrium
- It is a skectch of a body completely isolated or free from all other bodies.
Free body diagram
- It is a definite amount of matter the parts of which are fixed in position relative to on another.
Rigid body
- Its is the action exerted by one body upon another.
force
- A unit force
Newton
- The extenal effect of a force in a rigid body is the same for all points along its line of action
Principle of transmissiblity of a force
- The resultant of two forces is the diagonal formed on two vectors of thos forces
Parallelogram law
- The forces are in equilibrium only when equal in magnitude opposite in direction and colinear in action.
Axioms of mechanics
190 It is a convenient corollary of the parallelogram law.
Triangle law
- The determination of the resultant of 3 or mote concurrent forces that are not colinear.
resultantof concurrent, coplanar
- Addition which is followed by the parallelogram law desscribed by the figure.
addition of the vector
- An object with inertia but of negligible dimension
Particle
- A particle is in equilibrium if the resultant
Equilibrium equation for a particle
- In a rectangular coordinate system, the equilbrium equation can be represented by three sacalar equations.
Equilibrium equation in component form
- A mechanical device that can onlu transmit a tensile force along itself.
string or cable
- A mechanical device that can which exerts a force along its line of its action and propotional of its extension.
Linear spring
- The tension in the cable is the same on both sides of the pulley.
Frictionless pulley
- Each action has a reaction has a reaction equal in magnitude and opposite in direction.
newton’s 3rd law
- Forces and couples which are a result of interaction between one part of an object and another part of it will not appear in the free body diagram of the whole object.
Composite bodies and external source
