Force and Motion Flashcards
Velocity vs Time graph area
displacement
position vs time graph slope
velocity
velocity vs time graph slope
acceleration
acceleration vs time graph area
velocity
static friction
frictional force that prevents 2 surfaces from sliding
the upper limit is static coefficient x normal force
increasing stretch will increase friction
equal to the magnitude of the applied force
coefficient of static friction
based on properties of the surfaces involved
kinetic friction
friction when two surfaces slide against one another
friction drops once moving and then remains constant
kinetic vs static friction
kinetic friction has a lower coefficient than static
so kinetic friction will always ben lower than static friction
nonconservative force
energy is not conserved in the system and will dissipate in other forms of energy like heat and sound
ex: friction
nonconservative vs conservative force in work equation
nonconservative force will use total distance because the energy is not contained within the system
work down and back is W=F(2L)
conservative force will use displacement because energy is contained
therefore the work when down and back is 0
acceleration
change in velocity/change in time
vacuum
lacks particles so no sound
or anything that needs to be carried through matter
attenuation
dampening
decreasing amplitude, increases with distance
occurs mostly in soft materials
sound
propagates through vibrations of molecules as longitudinal pressure waves
compression is on peaks
rarefaction is on troughs
fastest in solids
does not occur in vacuums
vectors
magnitude and direction
displacement, velocity, acceleration, force
scalars
quantity without direction
speed, coefficient of frition
dot product
ABcos(theta)
cross product
ABsin(theta)
displacement
change in position; path independent
distance
path traveled
velocity
Δx/t
force
push or pull that creates acceleration
F=ma
Friction
opposes motion
acceleration
Δv/Δt
velocity vs time graph slope
Newton’s First Law
an object in motion stays in motion, an object at rest stays at rest if no net force
inertia
Newton’s second law
F= ma
Newton’s third Law
every force has an equal and opposite force
Kinematics (no displacement)
V=V(0) + at
Kinematics (no final velocity)
X = V(0)t + (at^2)/2
Kinematics (no time)
V^2 = V(0)^2 + 2ax
Kinematics (no acceleration)
x = vt
torque
T = rFsin(theta)
clockwise = negative counterclockwise = positive
Gravitational equation
Gmm/r^2
remember that Force is indirectly proportional to r^2
and directly proportional to mass
Centripetal force
F = mv^2/r
surface tension
cohesive forces that resist changes to movement
surface tension decreases with heat and increased surface area (stretches molecules)
Ts = F/d (force/distance)
electric forces
generated by voltage source and by intrinsic electrical properties of material
unaffected by temperature
center of mass
the system of point masses where the mass x radius is added for every point and then divided by the total mass to find where the equal/balance point is
This changes as someone grows taller
mechanical advantage
ratio of output force Fo to input force Fi
Fo/Fi = Di/Do
can use this when trying to lift heavier things - input 20N of force to be able to move something that is 400N (math doesn’t work out)
