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66 Cards in this Set
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What is the velocity of an object if you only know its acceleration, ∆time and initial speed?

v=vₒ+at


What is the velocity of an object if you only know its acceleration, ∆time, and displacement?

x=xₒ+vₒt+½at²
or v²=vₒ²+2a(xxₒ) 

What is force defined as?

Mass (m) times acceleration (a)


What is the force of friction always less than or equal to?

µN
(coefficient of friction times the normal force) 

What is the equation for centripetal acceleration?

a= v²/r
r= radius of circle 

What is the equation for torque?

τ=rFsinθ
(torque = radius * force * sin theta) 

What is the equation for momentum?

p=mv
(momentum = mass * velocity) 

What is the equation for impulse?

J=F∆t=∆p
(impulse = force * time = change in momentum) 

What is the equation for kinetic energy?

KE=½mv²


What is the formula for the potential energy of a falling object?

∆Ug=mgh
(mass * gravity * height) 

What is the equation for work?

F*d*cosθ
(force times distance (distance can also be a radius) times cosine theta) 

What is the equation for average/mean power?

W/∆t
(work divided by time elapsed) 

What is the equation for power (at a given instant)?

P=Fv*cosθ
(power = force * velocity * cosine theta) 

What equation can you use to fin d the spring constant?

F=(k)x
(force = negative spring constant * displacement) 

What is the potential energy of a vertical spring?

½kx²
(half of the spring constant times the displacement squared) 

What is the period of a spring?

2π√(m/k)
(2 pi times the square root of the mass (hanging) divided by the spring constant) 

What is the period of a pendulum?

2π√(l/g)
(2 pi times the square root of the length divided by gravity  mass is irrelevant) 

What is the period equal to (in terms of frequency)?

Its reciprocal. T=1/f


What is the equation for the force of gravity acting in between two objects?

G(m1)(m2)/r²
(negtative) universal gravitational constant (G) times the first mass, times the second mass divided by the distance between the two objects squared 

What is the gravitational potential energy between two objects?

G(m1)(m2)/r
(negative) universal gravational constant (G) times the first mass times the second mass divided by the distance between the two objects 

What is the equation for electric force?

F= 1/4πεₒ * (q1)(q2)/r²
(force equals one over 4 * pi * the vacuum permittivity constant, times the first charge * the second charge divided by the distance between the charges squared) 

What is the equation for electric field?

E=F/q
(electric field is equal to force divided by charge) 

What is the potential energy of an electric field?

UE=qV=F= 1/4πεₒ * (q1)(q2)/r
(potential energy = charge * voltage = force equals one over 4 * pi * the vacuum permittivity constant, times the first charge * the second charge divided by the distance between the charges) 

What is the equation for finding the average electronic field?

V/d
((negative) voltage divided by distance) 

What is the incredibly disgusting definition of voltage?

V=1/4πεₒ Σ(qi/ri)
(voltage is equal to one over 4 * pi * the vacuum permittivity constant times all of the point charges' charge divided by all of the point charges' distance 

What is the equation for capacitance?

C=Q/V
(capacitance = charge / voltage) or εₒA  d (vacuum permittivity constant * area divided by separation between two locations) 

What is the equation for potential/stored energy in a capacitor?

Uc=½QV=½CV²
(capacitor PE = one half time charge * voltage = one half times capacitance * voltage squared) 

What is the equation for average current?

∆Q/∆t
(change in charge divided by change in time) 

What is the equation for resistance?*
*not used by Thor 
ρl/A
(resistance = resistivity * length divided by area) 

What is voltage equal to?

V=IR
(voltage = current * resistance) 

What is power equal to (in electricity)?

P=IV
(power = current times voltage) 

How does one find the total capacitance of capacitors in parallel?

Add them up and treat them as one capacitor (much like resistors in a series circuit)


How does one find the total capacitance of capacitors in series?

It is equal to the reciprocal of the sum all the reciprocals of the capacitors' capacitance
(confusing enough wording?) 1 1 1 =+... C a b a and b being the capacitances of capacitors 

How does one find the total resistance of resistors in a series circuit?

Add them all up!


How does one find the total resistance of resistors in parallel?

It is equal to the reciprocal of the sum all the reciprocals of the resistors' resistance
(confusing enough wording?) 1 1 1 =+... R a b a and b being the resistance of the resistors 

What is the equation for the force of a magnetic field?

FB=qvB*sinθ
(charge * velocity * magnetic field * sin theta) or FB=BIl*sinθ (magnetic field * current * length * sin theta) 

What is the equation to find the magnetic field (in point charges)?

µθ I
* 2π r (vacuum permittivity constant divided by 2 pi times current divided by distance) 

What is the equation for magnetic flux?

ϕ=BAcosθ
(magnetic field * area * cos theta) 

What is the equation for average electromagnetic field (ε)?

∆ϕ
 ∆t (the change in magnetic field divided by the change in time) 

What is the equation for an electromagnetic field?

ε=Blv
(magnetic field * length * velocity) 

What is the equation for pressure?*
*Thor didn't use this much at all 
P=Pₒ+ρgh
(pressure = initial pressure + density * gravity * height) 

What is the equation for buoyancy?

Fbuoy=ρVg
(pressure * volume * gravity) 

What's the relationship between two areas and volumes of a liquid?

(A1)(V1)=(A2)(V2)
(area 1 * volume 1 = area 2 * volume 2) 

What is a constant you can form from a gas pressure?
(this question sucks, sorry) 
P+ρgy+½ρv² = a constant
(pressure + density * gravity * height + one half of the density times velocity squared) 

What is the equation for the change in length of an object (while it's heating up/cooling)?

∆l=alₒ∆T
(change in length = coefficient of linear expansion times the initial length times the change in temperature) 

What is the equation for the rate of heat transfer?

kA∆T
 L (thermal conductivity times area times change in time divided by thickness) 

What is the equation for pressure?

P=F/A
(pressure = force / area) 

What is the universal gas equation?

PV=nRT=N(Kb)T
(pressure * volume = number of moles * universal gas constant * temperature)= number of molecules * boltzmann's constant * temperature) 

What is the equation for average molecular kinetic energy?

K=(3/2)(Kb)T
(average molecular kinetic energy = 1.5 * boltzmann's constant * the temperature) 

What is the equation for the rootmeansquare velocity (in thermal physics)?

Vrms=√(3RT/M)=√(3(Kb)T/µ)
(square root of 3 * the universal gas constant * the temperature divided by molar mass = the square root of 3 times boltzmann's constant * the temperature divided by the mass of the molecule) 

What is the equation for work done on a thermal system?

W=P∆V
(work = negative pressure times change in volume) 

What is the equation for the change of internal energy of a thermal system?

∆U=Q+W
(change in thermal energy = heat transferred to the system + work done on the system) 

What is the equation for efficiency (of heat engines and the like)?

e=abs(W/(Qh))
(efficiency = the absolute value of the work done on the system divided by the heat transferred to the system) 

What is the efficiency of a Carnot heat engine?

ThTc
 Th (hot temp  cold temp / hot temp) 

What is the velocity of a wave?

v=λ
(velocity = frequency * wavelength) 

What is the equation for the index of refraction of a substance?

n=c/v
(index of refraction = speed of light in a vacuum / speed of light in the substance) 

What is the equation/guideline for the refraction of light?

(n1)sinθ1=(n2)sinθ2
(the index of refraction of the first substance times the sine of the angle (to the normal) = the index of refraction of the second substance times the sine of the second angle (to the normal) 

What is the equation for the critical angle of a substance?

sinθ=n2/n1 (n1>n2)
(the sine of the critical angle is equal to the first index of refraction of a substance divided by the second) 

What is the equation for a focal length?

1 1 1
=+ f do di (the reciprocal of the focal length is equal to the reciprocal of the object distance + the reciprocal of the image distance (don't forget to take the reciprocal of 1/do + 1/di when you're done adding them!) or f=R/2 (focal length = radius (of curvature)/2) 

What is the formula for the magnification of an object?

hi si
= hₒ sₒ (magnification = height of image divided by height of object or distance of image to lens from object to lens) 

What is the equation for doubleslit interference?

dsinθ=mλ
(separation between slits * sine of the angle = maxima # or an integer * wavelength) 

What is the equation for the separation between maxima?

mλL
 d (an integer or maxima # * wavelength * distance divided by separation) 

What is the equation for energy of a particle?

E=hf=pc
(energy = planck's constant * frequency = momentum * speed of light in a vacuum) 

What is the maximum kinetic energy of a particle?

Kmax=hfϕ
(max KE = planck's constant * frequency  work function) 

What is the wavelength of a particle?

λ=h/p
(wavelength = planck's constant / momentum) 

What is the equation for the change in energy of a particle?

∆E=(∆m)c²
(change in energy = change in mass * the speed of light in a vacuum squared) 