LECTURE #1 - forces and vectors Flashcards
what is forces ?
- effect that one boy has on another
- a push or pull applied to an object
- that required to change the state of motion of an object (i.e., that which causes acceleration)
force (cause) →
acceleration (effect)
whats an example of a vector ?
force
what is force (push or pull) ?
causes deformation and / or motion
what is force (vector quantity) ?
magnitude, direction and point of application
what is the formula for force ?
F = ma
what unit is force in ?
newtons (N)
how to calculate a newton ?
mass x acceleration
what is gravity ?
-9.81 m/s²
what is the following referring to ?
“magnitude (size) and direction (orientation)”
force (a vector quantity)
what is a third unique characteristic of force ?
point of application (especially important relative to the determination fo moments or torques)
what are three characteristics of force ?
- magnitude
- direction
- point of application
- line of action
- angle of pull / orientation
when classifying forces what are the two types of forces ?
internal and external forces
what are internal forces ?
- refers to a force that acts within a system or object, influencing its internal components or elements
- these forces do not originate from external sources but result from interactions between different parts or elements within the system itself
- ex. muscle tension, ligament tension, bone compression
what are external forces ?
- act on an object as result of interaction with environment
- can include pushes, pulls, or any other interactions that originate from sources outside the system being analyzed.
what are contact forces ?
forces resulting from objects coming into contact
what are non contact forces ?
forces that occur even if objects are not in contact
what are some examples of non contact ?
gravity, magnetic, electrical
what are two classifying forces ?
normal force and tangential force
what is normal force ?
force acting perpendicular to surface of object
what is an example of normal force ?
gravity pulling you down is an example
what is tangential force ?
force action parallel to surface of object
what is an example of tangential force ?
orientation is parallel
what is contact force ?
A force that requires physical touch or contact between objects to be exerted. It acts only when two objects are in direct contact with each other
what is non-contact force ?
A force that can act between objects even when they are not in direct physical contact
what are some types of contact forces ?
- ground reaction force (GRF)
- joint reaction force (JRF)
- friction
- fluid resistance
- inertia force
- muscle force
- elastic force
what are some types of non contact forces ?
gravity, magnetic and electrical
TRUE OR FALSE ?
forces usually act in pairs or in bodies ?
true
what is net force ?
single resultant force derived from the vector composition of all acting forces
TRUE OR FALSE?
net force determines the net effect of all acting forces on a body
TRUE
what are type of variables ?
scalars and vectors
what is scalars ?
a quantity that is defined by its size/magnitude
what are some examples of scalars ?
mass, energy, power, temperature, etc…
what is vectors ?
a quantity that is defined by its size/magnitude AND direction
how do we represent vectors ?
as arrows (length and pointing)
what is length represented as ?
size/magnitude
what is pointing represented as ?
direction
what are some examples of vectors ?
force, moment, velocity, acceleration, etc.
what is vector composition ?
the process of determining a single force (vector) from two or more forces (vectors) by vector addition (finding the resultant vector or net vector_
what are the two types of vectors that steps depend upon ?
collinear and concurrent vectors
what are colinear vectors ?
share the same line of action (parallel with each other
what are concurrent vectors ?
do NOT share the same line of action
TRUE OR FALSE
colinear forces that have the same line of action can be same or opposite direction and tip to tail ?
TRUE
how is the resultant found ?
by drawing an arrow from eh tail of the first force to the tip of the lat force
FILL IN TH BLANK
composition of vectors with _____ __________ requires adding their magnitudes
same direction
what type of forces “do not act on the same line, but they do act through the same point” ?
concurrent forces
what formula do we use to solve the missing side of a triangle ?
A² + B ² = C ²
what is a vector ?
mathematical object that has both magnitude and direction
what is force ?
is a push or pull that can cause an object to accelerate, decelerate or deform
