Chapter 3

Question 1

mass

Answer 1

Amount of matter in a body (m); units are kg

Question 2

inertia

Answer 2

resisting change in state of motion; keeps things in place; proportional to mass

Question 3

Force

Answer 3

push or a pull

Question 4

kinetics

Answer 4

study of forces

Question 4

Force formula

Answer 4

F (Newtons) = mass (kg) ✖️ acceleration (m/s^2)

Question 6

free body diagram

Answer 6

Diagram showing vector representations of all forces acting on a defined system

Question 7

net force

Answer 7

single resulting force taken from the vector composition of all the acting forces; force that determines the net effect of all acting forces on a body

Question 8

center of gravity

Answer 8

+Point where body’s weight is equally balanced in all directions

Question 9

Weight formula

Answer 9

wt. (Newtons) = mass (kg) x ag (acceleration of gravity: -9.81 m/s2)

Question 10

1 lb. = _ kg

Answer 10

2.2 kilograms

Question 11

1 lb. = _ N

Answer 11

4.45 Newtons

Question 12

pressure

Answer 12

Force per unit of area over which the force acts; describes force distribution within a fluid

Question 13

stress

Answer 13

Force per unit of area over which the force acts; describes force distribution w/in a solid

Question 14

Pressure/ stress formula

Answer 14

Pressure (Newtons/cm^2) = Force (newtons)/Area (cm^2)

Question 15

volume

Answer 15

Space occupied by a body; has 3 dimensions (w, h, and depth); units are m3 and cm3

Question 16

density

Answer 16

Mass per unit of volume; p (kg/m^3) = mass (kg)/volume (m^3)

Question 17

specific weight

Answer 17

Weight per unit of volume; units are N/m3

Question 18

impulse

Answer 18

product of force and the time over which the force acts; J (N•s) = Force (newtons) • time

Question 19

weight

Answer 19

Attractive force that the earth exerts on a body

Question 20

torque

Answer 20

rotary effect of a force; angular equivalent of force

Question 20

torque formula

Answer 20

T (newton meters {N-m}) = Force (newtons) • d (perpendicular distance from the force’s line of action to the axis of rotation)

Question 21

compression

Answer 21

Pressing or squeezing force directed axially through a body

Question 22

tension

Answer 22

Pulling or stretching force directed axially through a body

Question 23

shear

Answer 23

Force directed parallel to a surface

Question 24

bending

Answer 24

Asymmetric loading that produces tension on 1 side of a body’s longitudinal axis and compression on the other side

Question 25

torsion

Answer 25

Load producing twisting of a body around its longitudinal axis

Question 26

deformation

Answer 26

Change in shape; an effect of loading

Question 27

repetitive loading

Answer 27

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

Question 28

acute loading

Answer 28

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