Transcript ss06

FORCE DEFINED
Push or Pull
Rub
Blow or Impact
g
causes change in motion or shape of a body
Kinetics - forces
bouyancy
centripetal
elastic
fluid drag
fluid lift
friction
gravity
muscle
pressure
reaction
PROPERTIES OF A FORCE
1. M_____________
2. D______________
3. P A______________
4. L A_______________
MASS
Scalar quantity
common to solids, liquids, gases
measure of INERTIA
direct relationship between Mass & Inertia
Mass and Size NOT always direct
Mass is NOT a Force
WEIGHT
Vector
Weight is a Force
measure of force of g pulling downward
direct relationship between Weight & Mass
VOLUME
Objects of similar
VOLUME but
different MASS
Space that an object occupies
Length, Width, Height
NO relationship with Mass
Shot vs Softball
Table Tennis Ball vs
Golf Ball
DENSITY
Compactness of a body or object
Mass per unit of volume
Example
water = 9.90 Newtons per liter
air = 0.01 Newtons per liter
CENTER of GRAVITY
Center of Mass of an object or body
point where Mass is concentrated
balance point
See Figure C.2 on page 82
tooth pick on rim of glass
VECTORS
VECTOR COMPOSITION
Identify Resultant Magnitude & Direction
e.g. net force, velocity, acceleration, etc.
Using Trigonometry
e.g. Pythagorean theorem
VECTOR RESOLUTION
Resultant is KNOWN
Find the 2 components that comprise R
Steps:
1. draw given vector to a selected scale
2. from vector tail, draw horizontal line &  line
3. from head, connect lines to form a rectangle