Chapter 3 Flashcards
Inertia
tendency of a body to resist a change in it’s state of motion.
Mass
quantity of matter contained in an object.
Force
push or pull; the product of mass and acceleration.
Free body diagram
sketch that shows a defined system in isolation with all of the force vectors acting on the systems.
Net Force
resultant force derived from the composition o f two or more forces.
Center of Gravity
point around which a body’s weight is equally balanced, no matter how the body is positioned.
Weight
gravitational force that the earth exerts on the body.
Pressure
force per unit area over which force acts.
Volume
amount of three-dimensional space occupied by a body.
Density
mass per unit volume
specific weight
weight per unit volume
Torque
rotary effect of a force
Impulse
product of force and the time over which the force acts.
Compression
pressing or squeezing force directed through a body.
Tension
pulling or stretching force directed axially through a body.
Shear
force directed parallel to a surface.
Stress
distribution of force within a body quantified as force divided by the area over which the force acts.
Bending
asymetrical loading that produces tension on one side of a body’s longitudinal axis and compression on the other side.
Axial
directed along the longitudinal axis of a body.
Torsion
load producing twisting of a body around it’s longitudinal axis.
Combined Loading
simultaneous action of more than one of the pure forms of loading.
deformation
change in shape.
Yield Point (Elastic Limit)
point on the load deformation curve past which deformation are permanent.
Failure
loss of mechanical loading.
Repedative Loading
repeated application of a subacute load that is usually of relatively low magnitude.
Acute Loading
application of a single force of sufficient magnitude to cause injury to a biological tissue.
Myoelectric Activity
electric current or voltage produced by a muscle developing tension.
Transducers
devices that detect signals.
Vector
physical quantities that possess both magnitude and direction.
Scalor
physical quantity that is completely described by it’s magnitude.
Resultant
single vector that results from vector composition.
Vector Resolution
Operation that replaces a single vector with two perpendicular vectors such that the vector composition of the two perpendicular vectors yields the original vector.
