Physics Formulas Flashcards
Force
F.net = ma
Component vectors
X = V * cos(theta)
Y = V * sin(theta)
Pythagorean Theorem
A^2 + B^2 = C^2
Determination of direction from component vectors
(theta) = tan^-1 Y/X
Dot Product
|A|*|B|cos(theta)
Cross Product
|A|*|B|sin(theta)
Average Velocity
v = (delta)x/(delta)t
Universal gravitational Equation
F = Gm.1m.2/r^2
Static Friction
0 <= f.s <= (mu.s)N
Kinetic Friction
f.k = (mu.k)N
Newton’s First Law
F.net = ma = 0
Newton’s Second Law
F.net = ma
Newton’s Third Law
F.AB = -F.BA
Kinematics (no displacement)
v = v.0 + at
Kinematics (no final velocity)
x = v.0t + at^2 / 2
Kinematics (no time)
v^2 = v^2.0 + 2ax
Kinematics (no acceleration)
x = v.average * t
Component of Gravity on Inclined Plane
F.g.parallel = mg * sin(theta)
F.g.perpindicular = mg * cos(theta)
Centripetal Force
F.c = mv^2 / r
Torque
T = r X F = rF*sin(theta)
Kinetic Energy
K = 1/2 mv^2
Gravitational Potential Energy
U = mgh
Elastic Potential Energy
U = 1/2 kx^2
Total Mechanical Energy
E = U + K
Conservation of mechanical Energy
(delta)E = (delta)U + (delta)K = 0
Work done by nonconservative Forces
W.nonconservative = (delta)E
Definition of Work (mechanical)
W = F (dot) d = Fd cos(theta)
Definition of Work (isobaric gas-piston)
W = P (delta)V
Definition of power
P = W/t
Work-Energy Theorem
W.net = (delta)K
Mechanical Advantage
F.out/F.in
Efficiency
W.out/W.in
Fahrenheit to Celsius
F = 9/5 C + 32
Celsius to Kelvin
K = C + 273
Thermal Expansion Equation
(delta)L = (alpha) * L * (delta)T
Volume Expansion Equation
(delta)V = (beta) * V * (delta)T
First Law of Thermodynamics
(delta)U = Q - W
Heat gained of lost with temp change
q = mc (delta)T
Heat gained of lost (phase change)
q = mL
Entropy and heat
(delta)S - Q.rev/T
Second Law of Thermodynamics
(delta)S.universe = (delta)S.system + (delta)S.surroundings > 0
Density
(rho) = m/V
Weight of Volume of Fluid
F.g = (rho) * Vg
Specific Gravity
SG = (rho) / (1 g/cm^3)
Pressure
P = F/A
Absolute Pressure
P = P.0 + pgz
Gauge Pressure
P.gauge = P- P.atm = (P.o + pgz) - P.atm
Pascal’s principle
P = F.1/A.1 = F.2/A.2
F.2 - F.1 (A.2/A.1)
Buoyant force
F.bouy = (rho).fluid * V.fluiddisplaced * g = (rho).fluid * V.submerged * g
Poiseuille’s Law
Q = (pi) * r^4 (delta)P / (8(eta)L)
Critical speed
V.c = N.R * (eta) / ((rho) * D)
Continuity Equation
Q = v.1 * A.1 = V.2 * A.2
Bernoulli’s Equation
P.1 + 1/2 (rho) * v.1^2 + (rho)gh.1 = P.2 + 1/2 (rho) * v.2^2 + (rho)gh.2
Coulomb’s Law
F.e = kq.1q.2 / r^2
Electric field
E = F.e / q = kQ / r^2
Electric Potential Energy
U = kQq / r
Electric Potential (from electric Potential Energy)
V = U/q
Electric Potential (from source charge)
V = kQ/r
Voltage
(delta)V = W.ab / q
Electric Potential near dipole
V = kqd / r^2 * cos(theta)
Dipole Moment
p = qd
Electric field on perpendicular bisector of dipole
E = 1 / (4(pi)(epsilon).0) x p / r^3
Torque on dipole in electric field
T = pE sin(theta)
Magnetic field form straight wire
B = (mu).0 * I / (2(pi)r)
Magnetic field from wire loop
B = (mu.0) * I / (2r)
Magnetic force on moving point charge
F.B = qvB sin(theta)
Magnetic force on current-carrying wire
F.B = ILB sin(theta)
Current
I = Q / (delta)t
Kirchoff’s junction rule
I.intojunction = I.leavingjunction
Kirchhoff’s loop rule
V.source = V.drop
Definition of resistance
R = (rho)*L / A
Ohm’s law
V = IR
Voltage and cell emf
V - E.cell - ir.int
Definition of Power
P = W/t
Electric Power
P = IV = I^2 *R = V^2 / R
Voltage drop across circuit elements (series)
V.s = V.1 + V.2 + … + V.n
Voltage drop across circuit elements (parallel)
V.p = V.1 = V.2 = … = V.n
Equivalent resistance (series)
R.s = R.1 + R.2 + … + R.n
Equivalent resistance (parallel)
1/R.p = 1/R.1 + 1/R.2 + … + 1/R.n
Def’n of Capacitance
C = Q/V
Capacitance based on parallel plate geometry
C = (epsilon).0 * (A/d)
Electric field in a capacitor
E = V/d
Potential Energy of Capacitor
U = 1/2 C * V^2
Capacitance with dielectric material
C’ = (kappa)*C
Equivalent Capacitance (series)
1/C.s = 1/C.1 + 1/C.2 + … + 1/C.n
Equivalent Capacitance (parallel)
C.p = C.1 + C.2 + … + C.n
Concentration of Solution post dilution
M.iV.i = M.fV.f
Boiling Point Elevation
delta.T.b = iK.bm
Osmotic Pressure
II = iMRT
