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50 Cards in this Set
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Mean

u=Exi/N


Standard Deviation

St Dev= Sq. root( E(xiu)^2/(N1) )


displacement

disp=(fin. pos.)(init. pos.)


path length

s=total distance covered


speed at time t when acceleration is constant

v(t)=at+Vo


position at time t when acceleration is constant

S(t)=.5at^2+(Vo)t+So


average acceleration

a=(change in V)/(change in t)


Newton's 2nd Law

Fnetext=m*a where Fnetext is the sum of all forces acting on the object


Newton's 1st Law

a=0 if Fnetext=0


Newton's 3rd Law

(Force on 1 by 2)= (Force on 2 by 1)


Weight

W=Fg=mg
m=mass of object g=accel due to gravity (9.8m/s^2) 

Force of friction

f=uN


Work

W=Fd


Kinetic Energy

KE=.5(m)(v^2)


Potential Energy

PE=mgh


Conservation of Mechanical Energy

(Change in KE)=(Change n PE)


Ideal Mechanical Advantage

IMA=Se/Sr


Actual Mechanical Advantage

AMA=Fr/Fe


Torque

torque=Force*distance


Temperature Conversions

Tf=(9/5)Tc+32
Tc=(5/9)(Tf32) Tk=(Tc+273) 

First Law of Thermodynamics
energy is conserved 
(Change in U)=Q+W
U=internal energy of a thing Q=heat added to the thing W=work done on the thing 

First Law of Thermodynamics
(continued) 
Q=sm(change in T)
Qheat added to the thing s=specific heat of the thing m=mass of the thing (Change in T)=change in temp of the thing 

Energy Conversion

4.186 J/cal


Heat transfer by conduction

Q/t=(AK(T2T1))/d


Heat transfer by radiation

Q/t=eoA(T2^4  T1^4)


Pressure (of fluids)

P=F/A


Absolute (hydrostatic) Press.

Pabs=Po+dgh
usually Po=1atm d=density of liquid h=depth in liquid 

Gauge (hydrostatic) Pressure

P=dgh


Poiseuille's Law

FR=(P1P2)(pie*r^4/8xL)
FR=flow rate x=viscosity P1 and P2 are pressures at the end of a tube with length L and radius R 

Resistance to fluid flow

R=8xL/(pie*r^4)
x stills =viscosity 

Continuity Equation
flow rate remains constant for an incompressible fluid 
A1V1=A2V2
A=area V=flow speed 

Ideal Gas Law

PV=nRT P=pressure
V=volume n=# of moles T=temp R=8.32 J/moldeg 

Boyle's Law
special case of ideal gas law n and t are fixed 
P(initial)V(initial)= P(final)V(final)


Critical Velocity for onset of turbulence in a tube

Vc=Rx/dr x=viscosity
d=fluids density r=tubes radius R=reynold's # (about 1000) 

Laplace's Law of wall tension
(for cylindrical membranes) 
T=Pr


Laplace's Law of wall tension
(for spherical membranes) 
T=(Pr)/2


Bernoulli's Equation
energy per volume of ideal fluid remains constant 
E/V=.5d(v^2)+dgh+P=constant
.5d(v1^2)+dg(h1)+P1= .5d(v2^2)+dg(h2)+P2 

Coloumb's Law

F=(K(q1)(q2))/r^2
F=force b/w charges q1 & q2 separated by distance r K=9*10^9 Nm^2/C^2 

Current

I=(change in Q)/(change in t)
charge per time 

Relation b/w voltage and electric potential energy

PE=qV


Faraday's Law

V=N(change n z)/(change n t)
N=# of windings in wire loop z=magnetic flux 

Magnetic Flux through a wire loop

z=BA


Ohm's Law

I=V/R V=RI
I=current in amps V=voltage in volts R=resistance measured in ohms 

Power dissipated by resistor

P=IV P=(V^2)/R


Equivalent Resistance for series circuit

Req=R1+R2+R3....


Equivalent Resistance for parallel circuit

1/Req=1/R1+1/R2+1/R3....


Frequency of Household AC current

60 Hz


Current at threshold of feeling

1 mA


Maximum current harmless to humans

5 mA


Minimum current that can be fatal to a human

100300 mA
