Chapter 3

Question 1

Inertia

Answer 1

tendency of a body to resist a change in it’s state of motion.

Question 2

Mass

Answer 2

quantity of matter contained in an object.

Question 3

Force

Answer 3

push or pull; the product of mass and acceleration.

Question 4

Free body diagram

Answer 4

sketch that shows a defined system in isolation with all of the force vectors acting on the systems.

Question 5

Net Force

Answer 5

resultant force derived from the composition o f two or more forces.

Question 6

Center of Gravity

Answer 6

point around which a body’s weight is equally balanced, no matter how the body is positioned.

Question 7

Weight

Answer 7

gravitational force that the earth exerts on the body.

Question 8

Pressure

Answer 8

force per unit area over which force acts.

Question 9

Volume

Answer 9

amount of three-dimensional space occupied by a body.

Question 10

Density

Answer 10

mass per unit volume

Question 11

specific weight

Answer 11

weight per unit volume

Question 12

Torque

Answer 12

rotary effect of a force

Question 13

Impulse

Answer 13

product of force and the time over which the force acts.

Question 14

Compression

Answer 14

pressing or squeezing force directed through a body.

Question 15

Tension

Answer 15

pulling or stretching force directed axially through a body.

Question 16

Shear

Answer 16

force directed parallel to a surface.

Question 17

Stress

Answer 17

distribution of force within a body quantified as force divided by the area over which the force acts.

Question 18

Bending

Answer 18

asymetrical loading that produces tension on one side of a body’s longitudinal axis and compression on the other side.

Question 19

Axial

Answer 19

directed along the longitudinal axis of a body.

Question 20

Torsion

Answer 20

load producing twisting of a body around it’s longitudinal axis.

Question 21

Combined Loading

Answer 21

simultaneous action of more than one of the pure forms of loading.

Question 22

deformation

Answer 22

change in shape.

Question 23

Yield Point (Elastic Limit)

Answer 23

point on the load deformation curve past which deformation are permanent.

Question 24

Failure

Answer 24

loss of mechanical loading.

Question 25

Repedative Loading

Answer 25

repeated application of a subacute load that is usually of relatively low magnitude.

Question 26

Acute Loading

Answer 26

application of a single force of sufficient magnitude to cause injury to a biological tissue.

Question 27

Myoelectric Activity

Answer 27

electric current or voltage produced by a muscle developing tension.

Question 28

Transducers

Answer 28

devices that detect signals.

Question 29

Vector

Answer 29

physical quantities that possess both magnitude and direction.

Question 30

Scalor

Answer 30

physical quantity that is completely described by it's magnitude.

Question 31

Resultant

Answer 31

single vector that results from vector composition.

Question 32

Vector Resolution

Answer 32

Operation that replaces a single vector with two perpendicular vectors such that the vector composition of the two perpendicular vectors yields the original vector.