Kinematics and Dynamics Flashcards
vector quantity has…
magnitude and direction
scalar quantity has…
only magnitude
dot product
A . B = |A| |B| cos θ
cross product
A x B = |A| |B| sin θ
vector of position, only final and initial taken into account
displacement
scalar of position, considers path taken
distance
velocity (v)
vector,
v = ∆X/∆t (m/s)
acceleration (a)
vector,
a = ∆v/∆t (m/s^2)
SI unit of force (F)
vector,
Newtons (N) = kg*m/s^2
gravitational force between two objects
Fg = (Gm1m2)/r^2
where:
G = 6.67E-11 N*m^2/kg^2
force that opposes movement between stationary object and surface
static friction (fs)
static friction (fs)
fs ≤ μs*N
μs = coefficient of static friction (depends on two materials)
N = normal force, component force perpendicular to plane of contact
force that opposes movement between sliding object and surface
kinetic friction (fk)
kinetic friction (fk)
fk = μk*N μk = coefficient of kinetic friction (depends on two materials)
amount of matter in an object (scalar)
mass
measure of gravitational force on an objects mass (vector)
weight (W)
weight (W)
W = m*g
m = mass
g (Fg) = 9.8 m/s^2 (approximately 10) (on earth)
center of mass/gravity of uniform object
x = ( (m1x1) + (m2x2) + (m3x3) + …) / (m1 + m2 + m3 + …)
same for y and z, just replace x
Newton’s laws
F = m*a , Fab = -Fba F = force m = mass a = acceleration Fab = force from a to b -Fba = equal and opposite reaction
equations of linear motion
x = v*t x = v(o)*t + (1/2) a*t^2 v = v(o) + a*t v^2 = v(o)^2 + 2*a*x
where v(o) = velocity initial
forces that cause an object to move in a circular path, object has a tendency to break out of circular path
circular motion
keeps object from breaking out of circular motion path, always points radially inward
centripetal force
generated by centripetal force
centripetal acceleration
centripetal acceleration (Fc)
Fc = m*v^2 / r
happens when force applied to object that causes it to rotate
rotational motion
fixed point object rotates around
fulcrum
generated by application of force at some distance; clockwise is positive, counterclockwise is negative
torque (𝜏)
distance between applied force and fulcrum
lever arm
torque (𝜏)
𝜏 = r*F = r*F sin θ r = length of lever arm F = magnitude of force θ = angle between lever arm and force vectors
state of the absence of any net forces acting on an object
translational equilibrium
state of the absence of any net torques acting on an object
rotational equilibrium
