TH EGN Final study
True
(T/F) Scalars can be negative.
false
(T/F) Vector magnitudes can be positive or negative
a vector
Because moments have magnitude and direction, they are______________
opposite
If the solution yields a negative scalar, this indicates that the sense is___________
joints; external loads
Zero-force members occur at _______ where only two members are connected and ___________ do not act along either member.
Newton's Second Law
a particle acted upon by an unbalanced force F experiences an acceleration a that has the same direction as a force and a magnitude that is proportional to the force
m=2j-3
a simple truss formula
Concurrent
lines of action intersect
Coplanar
lying in the same plane
distributed loads
some examples of_________________ are The pressure of the wind on the face of a sign. The pressure of water within a tank. The weight of sand on the floor of a storage container.
Newton's Third Law
the mutual forces of action and reaction between two particles are equal, opposite and collinear.
The position vector is used to determine the unit vector of the line
the unit vector of a line is determined such that the dot product can be utilized to find the projection of the given vector along this same line. How is the unit vector determined?
Partially constrained
A body has fewer reactive forces than EoE.
Redundantly constrained
A body has more supports than EoE.
mass; size
A particle has a ________________ but a ________________ that can be neglected
particles; fixed
A rigid body has a number of _____________ that remain at a ____________ distance of each other
Newton's First Law
An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force. (law of inertia)
lb/ft
Distributed load units in FPS
N/m
Distributed load units in SI
perpendicular
For systems where the forces are concurrent, coplanar, or parallel, further simplification can occur because resultant force and resultant moment are:
magnitude
For the scalar formulation, F is the_______________ of one of the forces
moment arm
For the scalar formulation, d is the perpendicular distance or _____________ between the forces
multiforce members; frames; machines
Frames and machines are two types of structures which are often composed of pin-connected__________________. _________________ are used to support loads, whereas ____________ contain moving parts and alter the effect of forces.
tension
If the force tends to elongate the member, it is a _________________ force
3, 6
In three dimensions, particle equilibrium yields______________ equations and rigid body equilibrium yields ______________ equations
2, 3
In two dimensions, particle equilibrium yields____________ equations and rigid body equilibrium yields___________
couple moment
Moving a force vector that is not along its line of action will create the same external effects on the body if a _____________ is applied.
clockwise
Negative moments are_________________
Gusset plate
The joint connections are usually formed by bolting or welding the ends of the members to a piece of metal named as ____________________ that has a bunch of little spikes.
counterclockwise
Positive moments are______________
free
Since a couple moment can act at any point, it is considered a _________________ vector
Equilibrium
Statics has to do with the ______ of bodies.
particle;2
The MOJ is akin to______________ equilibrium. For each joint, there are __________________ equations that can be solved.
rigid body; 3
The MOS is akin to_______________ equilibrium. For each joint, there are_______________ equations that can be solved.
32.2 ft/sec^2
The acceleration due to gravity in FPS is________
kilogram
The base unit for mass in SI is
positive z-axis positive x-axis positive y-axis
The coordinate direction angles α, β, γ are determined between a vector and which of the following?
force vector, positive x-axis
The direction angle α (alpha) is measured between what two items (Select two responses):
a scalar
The dot product operation yields:
sections
The method of ____________ is used to determine the internal loads.
Improperly constrained
The reactive forces intersect at a common point or pass through a common axis or all the reactive forces are parallel.
Rigid Body Mechanics
This course focuses on which branch of mechanics?
perpendicular
Vector A dot product vector B = 0
tail
When adding together two vectors using the parallelogram law, the tail of one vector must be joined with the _____________________ of the other.
external forces and direction
When drawing an FBD of an entire body, which of the following is shown:
Fixed support
Which of the following is the most restrictive 2-D support?
fixed support
Which of the following is the most restrictive 3-D support?
The dot product of the unit vector of the axis with the moment created by the force.
Which operation gives the projection of the moment along an axis?
Collinear
having the same line of action
assumed
he sense (a.k.a. direction) of a force or couple moment having an unknown magnitude but known line of action can be_____________
Compression
if it tends to shorten the member, it is a ___________ force
