Physics 117 Equation Sheet
MECHANICS
For constant acceleration, ax:
(same for y-motion)
Quadratic equation:
Relative velocity:
Dynamics:
Friction:
(kinetic),
(static)
For circular motion:
Newton’s law of gravity:
,
Spring Force:
Work:
,
Energy:
(non-conservative)
(kinetic energy),
(gravitational potential energy)
(spring potential energy)
(Average) Power:
,
Momentum:
STATICS
Torque:
,
(impulse)
(d=lever arm)
Center of gravity (mass):
FLUIDS
(density)
(pressure)
Variation of pressure
with depth in a static fluid:
Archimedes’ principle:
Equation of Continuity:
Bernoulli’s equation:
HEAT
Thermal expansion:
(linear),
Conduction of heat:
= rate of heat energy transfer
Stefan’s Law:
(area),
(volume)
= rate of energy radiated
WAVES
(speed),
Speed of wave on a string:
Speed of sound wave in air:
(period),
(F = tension, μ = m/L = mass per unit length of the string)
(T in Kelvin units)
1
Doppler effect:
(for mechanical waves, observer moving with vo, source moving with vs)
(for EM waves, observer and source moving with relative speed, u)
(I = intensity, P = sound power),
Sound:
Simple Harmonic Motion equation:
,
ELECTROMAGNETISM
Coulomb’s Law:
= electric force
Electric fields:
(point charge)
(parallel plates)
Electric potentials:
(potential for point charge),
(electric potential energy change)
(potential difference across parallel plates separated by x)
Circuits:
,
,
(series)
Magnetic Forces:
(parallel)
(point charge),
Magnetic Fields:
(current carrying wire)
(long wire),
(center of loop with N turns)
(field inside solenoid with n turns/length)
= magnetic flux through A
Induction:
= Faraday’s/Lenz’s Laws,
(motional emf),
(generator)
Note: the directions for magnetic vector quantities are obtained using the right-hand rule.
Torque on a current loop:
LIGHTS AND OPTICS
Snell’s Law:
Thin Lens Equation:
, p = object distance, q = image distance, f = focal length
Magnification Equation:
A
DATA
,
circumference =
,
,
h
,
G = 6.67  10
2
g = 9.80 m/s ,
-11
Nm2/kg2
standard atmospheric pressure = 1.013  10 Pa ,  (water) = 1000 kg/m3
5
σ=
(Stefan-Boltzmann constant)
speed of sound in air at 20 C, v = 343 m/s ,
o
elementary charge:
proton mass:
,
threshold of hearing, Io = 1.0  10-12 W/m2
electron mass:
speed of light in a vacuum:
2