Fundamental Concepts of Force Flashcards
Kinetics
study of forces acting on body
displacement
motion of a body/segment that occurs when force is applied (i.e., change in angular position)
force
push or pull that causes displacement
equilibrium
equal and opposite forces
if forces are unbalanced, movement occurs in the direction of the ______________.
stronger force
when a force acts on an object, it can:
deform it
change its state of motion (move it, stop it, slow it down)
2 properties of force =
magnitude
direction
normal force/ground reaction force
If a person is standing on the floor, the floor/surface applies a normal force on the person so that the magnitudes of the two forces are equal. The reactionary force exerted by the ground is the ground reaction force.
- In reality, GRF is hardly ever comprised of just a normal (vertical/perpendicular) force
compression
a force, applied perpendicularly to the contact surface that pushes or pulls one object against the other
tension
application of one or more forces that pulls apart or separates a material (aka distraction force)
shear force
where an object exerts a force parallel to something else
friction force
when one surface slides over another. Depends on surface properties involved.
Magnitude is directly proportional to the normal force of the surface on the object
F(friction) = U x N
where U = coefficient of friction
coplanar force
all forces are acting on an object or body in the same 2D plane or surface
collinear force
if all forces have common line of action (i.e., tug of war)
concurrent forces
if multiple forces (system of forces) have lines of action that have a common point of intersection
external force
a force from outside the object/body, acting upon that object/body
internal force
a force from within the object/body; internal force may hold the object/body together when it experiences external forces
gravitational force
force exerted by earth on an object (i.e., weight); it is always directed straight down (vertically)
-magnitude = (mass of object)*(magnitude of gravitational acceleration)
mass
a property of a body
-The amount of matter contained within an object