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50 Cards in this Set
- Front
- Back
Mean
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u=Exi/N
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Standard Deviation
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St Dev= Sq. root( E(xi-u)^2/(N-1) )
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displacement
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disp=(fin. pos.)-(init. pos.)
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path length
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s=total distance covered
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speed at time t when acceleration is constant
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v(t)=at+Vo
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position at time t when acceleration is constant
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S(t)=.5at^2+(Vo)t+So
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average acceleration
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a=(change in V)/(change in t)
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Newton's 2nd Law
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Fnetext=m*a where Fnetext is the sum of all forces acting on the object
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Newton's 1st Law
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a=0 if Fnetext=0
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Newton's 3rd Law
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(Force on 1 by 2)= (-Force on 2 by 1)
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Weight
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W=Fg=mg
m=mass of object g=accel due to gravity (9.8m/s^2) |
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Force of friction
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f=uN
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Work
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W=Fd
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Kinetic Energy
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KE=.5(m)(v^2)
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Potential Energy
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PE=mgh
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Conservation of Mechanical Energy
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(Change in KE)=(-Change n PE)
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Ideal Mechanical Advantage
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IMA=Se/Sr
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Actual Mechanical Advantage
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AMA=Fr/Fe
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Torque
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torque=Force*distance
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Temperature Conversions
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Tf=(9/5)Tc+32
Tc=(5/9)(Tf-32) Tk=(Tc+273) |
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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 |
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First Law of Thermodynamics
(continued) |
Q=sm(change in T)
Q-heat added to the thing s=specific heat of the thing m=mass of the thing (Change in T)=change in temp of the thing |
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Energy Conversion
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4.186 J/cal
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Heat transfer by conduction
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Q/t=(AK(T2-T1))/d
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Heat transfer by radiation
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Q/t=eoA(T2^4 - T1^4)
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Pressure (of fluids)
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P=F/A
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Absolute (hydrostatic) Press.
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Pabs=Po+dgh
usually Po=1atm d=density of liquid h=depth in liquid |
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Gauge (hydrostatic) Pressure
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P=dgh
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Poiseuille's Law
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FR=(P1-P2)(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 |
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Resistance to fluid flow
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R=8xL/(pie*r^4)
x stills =viscosity |
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Continuity Equation
-flow rate remains constant for an incompressible fluid |
A1V1=A2V2
A=area V=flow speed |
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Ideal Gas Law
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PV=nRT P=pressure
V=volume n=# of moles T=temp R=8.32 J/mol-deg |
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Boyle's Law
special case of ideal gas law -n and t are fixed |
P(initial)V(initial)= P(final)V(final)
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Critical Velocity for onset of turbulence in a tube
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Vc=Rx/dr x=viscosity
d=fluids density r=tubes radius R=reynold's # (about 1000) |
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Laplace's Law of wall tension
-(for cylindrical membranes) |
T=Pr
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Laplace's Law of wall tension
-(for spherical membranes) |
T=(Pr)/2
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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 |
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Coloumb's Law
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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 |
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Current
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I=(change in Q)/(change in t)
charge per time |
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Relation b/w voltage and electric potential energy
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PE=qV
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Faraday's Law
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V=-N(change n z)/(change n t)
N=# of windings in wire loop z=magnetic flux |
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Magnetic Flux through a wire loop
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z=BA
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Ohm's Law
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I=V/R V=RI
I=current in amps V=voltage in volts R=resistance measured in ohms |
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Power dissipated by resistor
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P=IV P=(V^2)/R
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Equivalent Resistance for series circuit
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Req=R1+R2+R3....
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Equivalent Resistance for parallel circuit
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1/Req=1/R1+1/R2+1/R3....
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Frequency of Household AC current
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60 Hz
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Current at threshold of feeling
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1 mA
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Maximum current harmless to humans
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5 mA
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Minimum current that can be fatal to a human
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100-300 mA
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