test 4- Final

Question 1

stresses and strains on the body

Answer 1

internal and material properties of biological materials (compression, tension, bending, torsion, shear)

Question 2

external forces that act on the body affect the movements of..

Answer 2

the entire boys and also impose loads that affect the internal structures

Question 3

internal structures of the body

Answer 3

cartilage, tendons; ligaments, bones, and muscle

Question 4

understanding of the mechanical properties of the internal structures is important for…

Answer 4

preventing injury and evaluating the causes of injury

Question 5

stress

Answer 5

the external forces that act on the body are resisted by internal forces and cause deformation of the body

Question 6

the amount of deformation produced is related to…

Answer 6

the stress caused by the forces and the material that is loaded

Question 7

Do the 2 rubber bands stretch as much as the single rubber band did under the same force?

Answer 7

the deformation (or stretch) of the 2 rubber bands was not as large as that of the single rubber band unless you exerted twice as much force (the stress of the 1 rubber band is 2x as large as the stress of the 2 rubber bands)

Question 8

mechanical stress

Answer 8

the internal force divided by the cross-sectional area of the surface on which internal force acts (stress may vary within an object and is associated with a specific internal surface)

Question 9

three principal stresses

Answer 9

tension, compression, shear

Question 10

SI Unit for Stress

Answer 10

N/m^2 (Pascals)

Question 11

static equilibrium

Answer 11

if the rubber band is held still in a stretched position; ignoring weight, the pulling force at each end must be equal

Question 12

the force of stress represents…

Answer 12

the resultant of all the individual intermolecular bond forces that act across the surface of the imaginary cut and hold the rubber band together

Question 13

the cross sectional area (stress)

Answer 13

is at the imaginary cut plane (analysis plane) used to define the stress at this plane

Question 14

stress=

Answer 14

internal force/CSA of the internal surface

Question 15

E=

Answer 15

change in length/ original length

Question 16

axial stresses (normal or longitudinal stresses)

Answer 16

tension and compression; acts perpendicular (or normal) to the analysis plane

Question 17

transverse stress

Answer 17

shear

Question 18

Tensile Stress

Answer 18

(rubber band example) is the axial or normal stress that occurs at the analysis plane as a result of a force or load that tends to pull apart the molecules bonding the object together at that plane

Question 19

which anatomical structures are longer in one dimension than in the other 2? (tension)

Answer 19

long bones, muscles, tendons, ligaments

Question 20

stress in such structures is typically analyzed by (tension)

Answer 20

considering analysis planes that cut through the structure perpendicular to its longest dimension

Question 21

the stresses that act perpendicular to the analysis planes (this the long acid of the structure are called

Answer 21

axial, normal, or longitudinal stresses

Question 22

axial loading (tension)

Answer 22

a loading situation in which the forces act in the direction of the long axis of the bone (if cut perpendicular stress could be determined in the bone)

Question 23

if the force tends to pull the bone apart and stress acts away from the analysis plane the stress is…

Answer 23

tensile stress

Question 24

if the cross sectional area changes as you move distally along its length what else changes?

Answer 24

the stress changes/varies (inversely)

Question 25

an object tends to deform by stretching or elongating in the direction of the…

Answer 25

external loads

Question 26

for most materials, this elongation is directly proportional to the…

Answer 26

magnitude of the stress

Question 27

in humans, very large tensile loads may…

Answer 27

sprain or rupture ligaments and tendons, tear muscles and cartilage, and fracture bones