Quiz #1 Flashcards
Scalar
Contains magnitude (+/-)
Examples of Scalar
Mass
Distance
Speed
Volume
Vector
Contains magnitude and direction
Represented by arrows
Examples of Vector
Velocity
Force
Acceleration
Force
A vector that tells you strength and direction of a push or pull
What is Force measured in?
Newtons (N) or kg(m/s^2)
Force Equation
F= mass x acceleration
Internal Force
Force that acts within an object or system
External Force
Force that acts on an object as a result of interaction with environment
Types of Internal Forces:
Compressive
Tensile
Shear
Examples of External Forces:
Friction
Weight
Contact
Examples of Compressive Forces:
Push ups
Barbell on shoulders
Examples of Tensile Forces:
Stretching
Hanging from a bar
Ankle sprain/strain
Cervical traction
Example of Shear Forces:
ACL tear
Weight
Force of gravity acting on an object
Weight Equation
W= mass x gravity
Contact Force
Forces that occur between objects (solid or fluid) in contact with each other
Examples of Contact Force:
Friction Normal contact Ground reaction force Fluid resistance Joint reaction force
Examples of Non-contact Force:
Gravitational force
Electrical force
Magnetic force
Normal Contact Force
Perpendicular component force
Acts perpendicular to the surfaces in contact
Friction Force
Parallel component Opposes motion (sliding) between objects
Ground Reaction Force
Combination of friction force and normal contact force
2 Types of Frictional Force:
Static (limiting)
Dynamic (sliding/kinetic)
Static Frictional Force
Two surfaces not moving relative to each other
Dynamic Frictional Force
Two surfaces moving or sliding relative to each other
T/F:
Dry friction (two solid surfaces in contact) is NOT affected by the size of the surface area in contact.
True
Resultant Forces
Addition of 2 or more force vectors
Net Forces
Sum of all forces acting on an object
Colinear Forces
Same line of action
Could be same or opposite directions
Concurrent Forces
Different line of action, BUT act through the same point
Static Equilibrium
State or condition of an object when it is not moving
