# Shared Flashcard Set

Statics Final
final
43
Engineering
04/28/2013

## Additional Engineering Flashcards

Term
 Mechanics
Definition
 Study of bodies at rest or in motion.
Term
 Statics
Definition
 Study of bodies at rest or in equilibrium.
Term
 1 2 3 5
Definition
 Which six principles of Mechanics apply most often in statics.1. Law of addition of forces2. Principle of transmissibility of forces3.Newton's first law4.Newton's 2nd law5.Newton's 3rd law6.Newton's Law of Gravitation
Term
 Particle (shape,size ignored)Rigid Body (changes in shape,size ignored)Deformable body (changes " " not ignored)Fluids (Liquids incompressible, gases compressible)
Definition
 Real body simplified for analysis as:
Term
 Force (vector quantity)
Definition
 Action of one body onto another; characterized by its point of application, magnitude, LOA, and sense
Term
 External or Internal (to the body)Planar or Spatial (one plane or 3-D)Concurrent or non-concurrent (parallel or non parallel)
Definition
 A force can be either...
Term
 Vector
Definition
 Parameter possessing magnitude and direction which add according to the parallelogram law. Ex. displacements, velocities, accelerations.
Term
 Scalar
Definition
 Parameter possessing magnitude but not direction. Ex. mass, volume, temperature
Term
 Fixed or bound
Definition
 ______ vectors have well defined points of app. that cannot be changed without affecting an analysis.
Term
 Free
Definition
 _____ vectors may be freely moved in space without changing their effect on an analysis.
Term
 Sliding
Definition
 _____ vectors may be applied anywhere along their line of action without affecting an analysis.
Term
 Negative
Definition
 ______ vector of a given vector has the same magnitude and the opposite direction.
Term
 R2 = P2 + Q2 -2PQcosB R = P + Q
Definition
 Law of cosines
Term
 commutative P + Q = Q + P associative P + Q + S = (P + Q) + S = P + (Q + S)
Definition
Term
 Concurrent forces
Definition
 Set of forces which all pass through the same point
Term
 Vector force components
Definition
 two or more force vectors which, together, have the same effect as a single force vector.
Term
 Equilibrium
Definition
 When the resultant of all forces acting on a particle is zero, the particle is in...
Term
 If the resultant force on a particle is zero, the particle will remain at rest or will continue at constant speed in a straight line.
Definition
 Newton's first Law
Term
 Space diagram
Definition
 A sketch showing the physical conditions of the problem.
Term
 Free-Body Diagram
Definition
 A sketch showing only the forces on the selected particle.
Term
 system of forces
Definition
 A collection of forces acting at specific points of a rigid body is called a _____. Forces acting on the SAME BODY
Term
 equivalent
Definition
 Two systems of forces are said to be _______ if they have the SAME EFFECT on the rigid body.
Term
 Dot Product (scalar product)
Definition
 The result of this operation is scalar (numerically it could be postive or negative) It requires two vectors (binary operation). The product of the magnitudes of each of the two vectors and the angle between them.
Term
 Multiplying it by a unit vector along a known axis.
Definition
 To convert a scalar into a vector what operation is necessary which we learned in Chap. 2?
Term
 Commutative P•Q = Q•P Distributive P•(Q1 + Q2) = P•Q1 + P•Q2 Not associative (P•Q)•S = undefined
Definition
 Scalar products are...
Term
 Determine the angle given the two vectors. Determine the projection of one vector along a given axis.
Definition
 Two main applications of the dot product.
Term
 Cross product (vector product)
Definition
 _______ of two vectors P and Q is defined as the  new vector V which satisfies the following conditions. LOA of V is perpendicular to plane containing P and Q Magnitude of V is V = PQsinΘ Direction of V is obtained from the right-hand rule
Term
 Not commutative QxP = -(PxQ) Distributive Px(Q1 + Q2) = PxQ1 + PxQ2 Not associative (PxQ)xS not= Px(QxS)
Definition
 Vector products ( cross products) are....
Term
 Moment of a force
Definition
 is thus a measure of the effect of a force on a rigid body the tendency for roation (sometimes called a torque)
Term
 Couple
Definition
 Two forces of equal magnitude, opposite in direction AND their LOA separated by a finite distance.
Term
 ZERO Body is not in equilibrium b/c both forces tend to rotate the rigid body.
Definition
 Net (resultant) force of a couple...
Term
 Couple vectors
Definition
 Obey the law of addition of vectors, are free vectors the POA is not significant, may be resolved into component vectors.
Term
 A force-couple system
Definition
 The three forces may now be replaced by an equivalent force vector and couple vector.
Term
 force-couple systems
Definition
 A system of forces may be replaced by a collection of _______ acting at a given point O.
Term
 equivalent
Definition
 Two systems of forces are _______ if they can be reduced to the same force-couple system.
Term
Definition
 The force-couple system at O may be moved to O' with the _______ of the moment of R about O'
Term
 mutually perpendicular single force new LOA
Definition
 If the resultant force and couple at O are __________, they can be replaced by a _______ acting along a ______
Term
 1. the forces are concurrent 2. the forces are coplanar 3. the forces are parallel
Definition
 The resultant force-couple system for a system of forces will be mutually perpendicular if...
Term
 ∑F acting on it is zero (no net translational effect) ∑M due to all forces about any arbitrary point is also zero (no net rotational effect)
Definition
 The necessary and sufficient conditions of equilibrium for a rigid body is that...
Term
 six scalar equations.
Definition
 ∑F = 0 ∑Mo = 0 These two vector equations yield...
Term
 Reactions
Definition
 ...are responses of one rigid body on to another due to the constraints placed on the system of rigid bodies to serve a certain purpose. They prevent the 2nd body from translation or rotation or both. Are either forces or couples or both and thus provide required constraints.
Term
 # of unknowns > # of independent equations Fewer # of unknowns than equations, partially constrained Equal # of unknowns and equations but improperly constrained
Definition
 Statically Indeterminate Reactions
Term
 concurrent or parallel. If there is no single point of intersection then we could not show the sum of the moments about one point is zero.
Definition
 For equilibrium of a three-force body the lines of action of the three forces must be ________ or ________
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