Forces and Thier Measurements Flashcards
(36 cards)
Force
effect that one body has on another
Internal force
within the system
external force
outside of the system
is force a scalar or vector?
vector (magnitude and direction)
point of application of force
necessry for determining moments and torques
Pressure
Force/area
force is distributed “force per cross sectional area”
Newtons 1st law
Intertia
Newtons 2nd law
F=ma
newtons 3rd law
action reaction
free body diagram
all external forces acting on the body
GRF
Ground Reaction Force
with no movement = to mass
GRF-W = ma
Positive Acceleration
increasing V - upward direction
decreasing velocity - downward direction
change direction from down to up
negative acceleration
decreasing V in upward Direction
increasing v in down direction
changing direction from up to down
zero acceleration
constant v
peak v
What does this graph and A and B represent?
Walking GRF - double bump
A weight acceptance
B. push off
Running GRF
In a biphasic wave what indicates velocity?
Slope of the line
What does friction do?
opposes the tendency to move
Ffriction=coefficient of friction * Normal reaction force.
In which direction does normal force exert its influence?
perpendicular to surface
As friction increases
force increases and vice versa
Cause of angular motion
eccentric force
centric force
-linear motion only
-line of action passes through objects COM
force couple
-angular motion only
-force with a resultant moment but no resultant force
eccentric force
general motion (linear/angular)