Physics Formulas
Electric potential
Electric potential = kQ/r Electric potential energy: qV
Stress
F/A
Pascal's law
F1/A1=F2/A2
Archimedes' principle
Fbuoyant = pfluid*Vsub*g
Centripetal force
Fc = mac = m*v^2/r
Gravity
Fgrav = mg = w Fgrav = G*Mm/r^2 g = G*M/r^2 gEarth ~ 10m/s
Newton's law
Fnet = 0 --> v = constant Fnet = ma F2-on-1 = F1-on-2
Friction
Fstatic < UsFN Fkinetic = UkFN
harmonic frequencies (closed ends)
*odd n
Current
I = Q/t
Impulse-momentum theorem
J = delta p
Capacitance with dielectric
K*Cwithout
period
T = 2pi * √m/k
centripetal acceleration
ac = v^2/r
law of reflection
angle of incidence = angle of reflection
cos and sin values
angles: 0, 30, 45, 60, 90, 120, 135, 150, 180 cos: √4/2, √3/2, √2/2, √1/2, √0/2, -√1/2, -√2/2, -√3/2, -√4/2 sin: √0/2, √1/2, √2/2, √3/2, √4/2, √3/2, √2/2, √1/2, √0/2 √2 = 1.4 √3 = 1.7
Doppler effect
approaching --> higher f receding --> lower f
Heisenberg uncertainty principle
deltax*deltap > h/2pi
frequency
f = 1/2pi * √k/m
frequency and period
f = 1/T T = 1/f
Volume flow rate
f = Av
focal length
f = R/2
harmonic frequencies (open ends)
fn=nf1
sound intensity level
in dB
magnification
m = -di/do
center of mass
m1x1+m2x2+.../m1+m2+...
velocity sound
v = √B/p
center of gravity
w1x1+w2x2+.../w1+w2+...
harmonic wavelength (open ends)
wavelength n = 1/n*wavelength 1
velocity (waves)
√Ft/u = √Ft/(m/L)
Stopping voltage
-eVstop = KEmax
harmonic wavelengths (closed ends)
4L/n *odd n
Potential Electrical Energy
1/2QV = 1/2CV^2 = Q^2/2C
kinetic energy
1/2mv^2
Temperature of monatomic ideal gas
1/2mv^2 = 3/2(kb)(T)
frequency of a simple pendulum
1/2pi*√g/L
Resistors in parallel
1/R=1/R₁+1/R₂+1/R₃+...
mirror-lens equation
1/do + 1/di = 1/f
Continuity equation
A1v1 = A2v2
capacitance
C = Q/V
capacitors in parallel
C=C₁+C₂+C₃+...
first law of thermodynamics
Delta E = Q-W Work: W = P(deltaV)
Hooke's law
Delta L = FL/EA Fs = -kx PEs = 1/2kx^2
Strain
Delta L/L
mechanical energy
E = KE + PE
electric field between plates
E = V/d
Energy of a photon
E = hf = hc/λ c = 3.0 x 10^8 m/s
conservation of mechanical energy
E2 = E1 aka K2 + U2 = K1 + U1 ∆PE = ∆KE If nc forces act during motion: Ei + Wnc = Ef
Projectile motion equations
X=Vot Vx=Vox ax=0 y=Voyt-1/2gt^2 Vy=Voy-gt ay=-g Vox = Vocos(theta) Voy=Vosin(theta)
lens power
P = 1/f Pcombination = P1 + P2
pressure
P = F(perpendicular)/A
Power in a circuit
P = IV = I^2R = V^2/R
Power in AC circuit
P = Irms*Vrms = Imax/√2 * Vmax/√2
Total hydrostatic pressure
P = Po + pgD = Patm + pgD (if Po=Patm)
Bernoulli's equation
P1 + pgy1 + 1/2pv1^2 = P2 + pgy2 + 1/2pv2^2
sound intensity
P=IA, where P=power, I=intensity, A=surface area
potential energy
PEgrav = mgh
Gauge pressure
Pgauge = P-Patm
Heat and temperature for an ideal gas
Q = nCv(delta T) --> constant volume Q = nCp(delta T) --> constant pressure
Resistance
R = V/I R = p*L/A
Resistors in series
Rs = R₁ + R₂ + R₃
work
W = Fdcos(theta)
Power
W/t, P = Fv is F is parallel to v and v is constant
work-energy theory
Wtotal = delta (KE)
index of refraction
n = c/v
Law of Refraction (Snell's Law)
n1sinθ1 = n2sinθ2
Density
p = m/v pH2o = 1000 kg/m^3
momentum
p = mv Impulse: J = Ft
ramp equations
perpendicular = normal = mgcostheta parallel to ramp = mgsintheta
Conservation of momentum
pi = total pf
Torque
rFsin(theta)
specific gravity
ratio of a mineral's weight compared with the weight of an equal volume of water p/pH2O
