AP Physics B Formula Study SheetNEWTONIAN MECHANICS

Kinematics Δx = area under v-t graph

Δv = area under a-t graph

displacement is a change in position; velocity is the rate of change of displacement, acceleration is the rate of

change of velocity

Net Force Fnet = mathe sum of all forces is proportional to mass x

acceleration

Friction force Ff = μFN

the friction force is proportional to the coefficient of friction x the normal force

centripetal accelerationthe acceleration of an object

experiencing UCM is equal to the speed2 / the radius

torque τ = rFtorque is equal to the

perpendicular distance x the force

momentum p = mvmomentum is equal to mass x

velocity

impulse J = FΔt = mΔvimpulse is equal to the change

in momentum

kinetic energyK = mv2 kinetic energy is ½ mass x

velocity2

gravitational potential energy

Ug = mghgravitational potential energy is mass x gravitational field x

height

mechanical work W = FΔxwork is the energy done by an

external force moving through a displacement

power (general definition)

P = power is the rate of energy

transfer

power in terms of velocity

P = Fvpower is the rate at which an external force moves through

a displacement

spring force Fs = kΔxthe force in a spring is equal to the spring constant x the

amount of stretch or compression of the spring

spring potential energy Us = kΔx2the energy stored in a spring = ½ x spring constant x the

stretch or compression

period of a spring Ts = the period of a spring depends on mass and spring constant

(not amplitude)

period of a pendulum Tp = the period of a pendulum

depends on length and gravitational field

relationship between period and frequency T =

period and frequency are reciprocals of each other

gravitational force between any two objects with mass FG =

any two masses exert a gravitational force on each

othergravitational potential energy between any two objects with

massUG =

any 2-mass system near has potential energy

FLUID MECHANICS AND THERMAL PHYSICS

absolute pressure in a fluid

P = P0 + ρgh

gage pressure P = ρgh

buoyant force Fbouy = ρVg

fluid flow continuity A1v1 = A2v2

volume flow rate A1v1

Bernoulli’s principleP + ρgy + ρv2 =

constantpressure (general

definition)P =

ideal gas law PV = nRT = NkBT

internal energy in a gas Kavg = kBT

velocity of a gas molecule

vrms = =

thermal workW = PΔV or area under

graphchange in internal

energyΔU = Q + W

efficiency (general) e =

ideal (Carnot) efficiency ec =

ELECTRICITY AND MAGNETISM

Electrostatic force Fe =

Electrostatic field E =

Electrostatic potential energy

Ue =

Electrostatic potential V =

Charge on a capacitor Q = VC

Capacitance C =

Energy stored in a capacitor

UC = ½ QV = ½ CV2

Current (definition)

I =

Resistance of a wire R =

Ohm’s Law V = IR

Power in a circuit

P = IV = =

I2REquivalent resistor for

seriesReq = R1 + R2 + …

Equivalent resistor for parallel

Req =

Equivalent capacitance for series

Ceq =

Equivalent capacitance for parallel

Ceq = C1 + C2 +…

Magnetic force on a moving charge in a

magnetic fieldFB = qvBsinθ

Magnetic force on a current carrying wire in

a magnetic fieldFB = BIlsinθ

Magnetic field around a current carrying wire

B =

Magnetic flux Φm = BAcosθ

Average EMF generated by a changing magnetic

fieldεavg =

EMF generated by a loop moving into or out

of a magnetic fieldε = Blv

Force BIl’s qvB

Take εast Blvd when the flux is changing.

WAVES AND OPTICS

Velocity of a wave v = fλ

Index of refraction n =

Snell’s Law n1sinθ1 = n2sinθ2

Critical anglen1sinθ1 = n2sin90 or

sinθc =

Mirror & lens equation

Magnification M =

Focal length in terms of radius of curvature

f =

Diffraction pattern path difference

mλ = dsinθ

Diffraction pattern spacing

xm =

ATOMIC AND NUCLEAR PHYSICS

Energy of a photon E = hf = pc

Maximum kinetic energy of an emitted electron

-φ + hf = Kmax

deBroglie wavelength of an emitted electron

λ =

Rest energy of a mass ΔE = (Δm)c2