deck_2435790-2 Flashcards
1
Q
Center of mass
A
Cmass= (r1m1+r2m2+r3m3…)/mtotal
2
Q
Newton’s 2nd law: Force
A
F=ma
3
Q
Avg velocity
A
Vavg=(V1+V2)/2
4
Q
Distance traveled
A
Distance=rate*time
5
Q
Range
A
Range=Vx*time
6
Q
Object falling-its distance traveled
A
X=1/2 at²
7
Q
Final velocity given drop height
A
V=√(2gh)
8
Q
Round trip times or time in the air
A
tair=2V/g*V=must be the vertical component of initial velocity
9
Q
At terminal velocity
A
mg=F air
10
Q
Force DUE to gravity or “inverse square law”* “G”*NOT gravity itself
A
F=Gm1m2/r²
11
Q
“gravity” or “the strength of the gravitational field” or “acceleration due to gravity” * “g”
A
g=Gm/r²
12
Q
Near earth, force due to gravity
A
F=mg
13
Q
Gravitational Potential energy*near earth
A
PE=mgh
14
Q
Gravitational Potential energy*in space, or near earth if NOT assuming g=10m/s²
A
PE= -Gm1m2/r
15
Q
Friction formulas
A
Ff= µ(static)Fnormal or Ff=µ(static)mgcosθFf= µ(kinetic)Fnormal or Ff=µ(kinetic)mgcosθsliding=kineticno sliding=static
16
Q
Force down an inclined plane, parallel to the surface
A
F = mgsinθ
17
Q
Normal force on an inclined plane (always perpendicular to surface)
A
Fn=mgcosθ
18
Q
Velocity of a particle at the base of an inclined plane
A
Vf=√(2gh)
19
Q
Hooke’s Law (springs)
A
F = k∆x*(where ∆x is the displacement ofthe spring from its equilibrium point, NOT thelength of the spring)
20
Q
Elastic Potential energy
A
PE = 1/2k∆x²*likely to be used in conservation of energy [KE–>PE]. This can tell us how far the spring will compress when something hits the spring1/2mv²= 1/2k∆x²
21
Q
Period of a Spring*(time needed for one complete cycle)
A
T = 2π√(m/k) [mass on a spring]*solving for frequency: just invert it T=1/f f=1/T
22
Q
Period of a Pendulum
A
T = 2π√(L/g) [pendulum]*solving for frequency: just invert it T=1/f f=1/T
23
Q
Torque
A
T=Fℓ*ℓ=lever arm
24
Q
Centripetal Force
A
Fc=mv²/rvelocity of satellite: mv²/r=Gm1m2/r²centriFUgal= the force “going away” from center of circle
25
How many radians in 1 circle
6 radians* 2π radians in 1 circle (360°) so... ≈ 6 radians
26
Angular velocity (ω) * "Rate of spin"
ω=2πf*f= frequency (Hz)ω=v/r*v=tangential velocity (m/s)*r=radius (m)
27
Circumference of a circle
C=2πr
28
Momentum
p=mv*Always conserved in an isolated system
29
Impulse * "average force"
Impulse=Δpor =mΔv
30
Elastic collisions *(bounce off)**Momentum & KE are BOTH conserved
1/2m1v1² + 1/2m2v2² = 1/2m1v1² + 1/2m2v2²(KE of object one before + KE of object two before= KE of object one after + KE of object two after)
31
Inelastic collisions**Momentum is conserved but KE is NOT*Energy goes to creating breakage, deformity, etc.
m1v1+m2v2 = m1v1 + m2v2YOU MUST USE SIGNS. Any velocity vector to the left or down must be given a negative signPerfectly inelastic: m1v1+m2v2=(m1+m2)v3
32
Stress
Force/Area
33
Strain
Δdimension/original dimension
34
Moduli of Elasticity (ME)
ME=stress/strain(force/area) / (Δdimension/original dimension)
35
Thermal Expansion
When solids are heated, they expand. When they are cooled, they shrinkΔL = αL0ΔTα: the Coefficient of linear expansionL0: Initial length of the objectΔL: Length change of the objectΔT: Temperature change of the object
36
Kinetic Energy
1/2mv²
37
Gravitational Potential Energy
PE= -Gm1m2/r ormgh (near earth)
38
Elastic Potential energy
PE = 1/2k∆x²
39
Electrical Potential energy
kqq/r orqEdorqV
40
Potential Energy stored by a capacitor
1/2 CV²*can be used with C=Q/V(Capacitance)
41
Mechanical Energy
KE+PE*In the absence of friction, drag etc., ME is always conserved
42
Work* Joules=N*mor(kg*m²)/s²
∆Energyor W = Fdcosθ or W=(Force)(Displacement)
43
Thermodynamics: work & heat are the only 2 ways Energy can be transferred into or out of a system
∆E=W + Q
44
Work-Energy Theorem*If a net force does work on a rigid object, the work done on that object is equal to the change in the KE of the object
W= KE final - KE initial
45
Force necessary to lift any mass w/o a machine (at constant velocity)
F necessary=mg
46
Ramps
Fm=mg(h/d)*h=height of ramp*d=distance of hypotenuse*Machines reduce the amount of FORCE necessary, but NEVER reduce the amount of work needed to be done!
47
Levers
Fm=mg (L1/L2)*L1=lever arm for mass*L2=lever arm for the applied force
48
Pulleys
Fm=mg/ (# of vertical ropes directly lifting the mass)
49
Hydraulic lifts
Fm=mg (h1/h2)*h1=distance traveled by large plunger*h2=distance traveled by small plungerorF=mg(A1/A2)*A1=cross-sectional area of small plunger*A2= of large plunger
50
Power
P=∆E/tP=W/t (work/time)P=Fdcosθ/tPi=Fvcosθ (Instantaneous power)Units: watts (J/s)Power of air resistance: P=Fv = -mgv
51
Coulomb's Law*Smaller atoms hold on more tightly to their electrons
F=kqq/r²
52
Work function
KE=E-φ (this symbol is the energy needed to eject an electron) (E=hf) This is energy of a photon*h=Plancks ConstantNOTE: Careful!! Increasing the intensity does NOT increase the energy of the ejected electron-i.e. shooting more photons at the metal only increases the # of electrons ejected when they have enough energy to even be ejected
53
Keq
[products]^x/[reactants]^y
54
Reaction Quotient, Q*Prod/React like Keq, but not calculated at equilibrium
Q>K LEFT/reactantsQ
55
Heat capacity*The Amt of energy (J or Cal) a system must absorb to give a unit change in temperature (J/K or cal/C)
C=q/∆T
56
Specific Heat capacity
q=mc∆T*Specific heat of water: 1.0 cal/g °C or4.18 J/g °C
57
Pressure-Volume (PV) work*Work is energy transfer via a force or a change in volume at constant pressure
PV work=P∆V*Requires constant pressure. ANY change in volume tells you there is PV work
58
Relationship: Temperature & KE
KE=3/2(kb)Tkb=Boltzmann's constant
59
Thermodynamic Relation
∆G=∆H-T∆S
60
Relationship: Keq & Gibbs free energy
∆G°= -RTlnKeq*ln of any positive number less than 1=NEGATIVEK>1=spontaneous
61
Dipole moment
µ=δdδ=charged=distance between charges
62
Density
D=m/v*H2O: 1000 kg/m^3 or 1.0 g/cm^3 1cm^3 (or 1 g/mL)=1mL1 L of H2O=1 kg1 mL of H2O=1 g
63
Specific Gravity*How dense something is compared to H2O
SG=D substance/D H2O
64
Buoyant Force
F buoyant=pvgp=density of fluid
65
Apparent Weight (AW)
AW=Actual Weight (aW) - F buoyant
66
General Pressure formula
F/A*Units: Pascals, mmHg, atm or Torr*All formulas give PASCALS* 1X10^5 Pascals= 1 atm= 760 mmHg=760 Torr
67
Fluid Pressure
P=pgh
68
Flow Rate
Q=AVA=cross-sectional areaV=velocity
69
Cardiac Output
CO= Stroke Vol * Heart Rate
70
Bernoulli's Equation
K= P + pgh + 1/2pv²*P=pressure energy*pgh= gravitational PE per volume (h=height, not depth)*1/2pv²= KE per volume of fluidApplication:* In a horizontal pipe, if fluid Velocity INC, Pressure DEC*Velocity of H2O exiting a spigot: PE of H2O at top of tank (pgh) is converted to KE of H2O leaving at the spigot (1/2pv²)
71
Charge
( - ) neg= electrons( + ) pos= fewer electrons
72
Charge is quantized
e - = 1.6x10^-19 C
73
Force: point charge in E-field
F=Kqq/r² (Coulomb's Law)*Force for real gravity: F=Gmm/r²
74
Force: constant E-field
F=qE*Force for gravity near earth: F=mg
75
Strength of the field: constant E-field
E=F/q (or E=V/d)*Strength of field for gravity near earth: F=mg
76
Strength of the field: point charge E-field
E=Kq/r²*Strength of field for real gravity: Gm/r²
77
Electrical PE: for point charge E-field
PE= -Kqq/r or Kqq/r*PE for real gravity: PE=-Gmm/r
78
Electrical PE: for constant E-field
PE=qEd*PE for gravity near earth: PE=mgh
79
Voltage: for point charge E-field* "PE"
V=Kq/r (specific to 2 point charges)*For real gravity: V=Gm/r
80
Voltage: for constant E-field
V=Ed*For gravity near earth: V=gh
81
Magnetic force exerted on a charged particle moving in a magnetic field
F=qvBsinθ*θ= angle between v & B*units: B= N*s/C*m or Kg/A*s²
82
Right hand rule: Field produced by current
Thumb=currentFingers=magnetic field (curled-like you're grabbing the wire)
83
Right hand rule: Force on a charged particle
Thumb=velocityFingers=magnetic field (straight)Palm=force* + charge: use RIGHT hand - charge: : LEFT hand
84
Current
I=∆q/∆t*Amount of charge (i.e. electrons) that flows past a fixed point per unit time
85
Resistance
R=pL/Ap=resistivityL=lengthA=cross-sectional area
86
Voltage
V=PE/q
87
Ohm's Law
V=IR
88
Capacitance
C=Q/V
89
Capacitor's PE
U= 1/2CV²
90
Intensity of a sound
I ∝ A²f²*Intensity is directly proportional to the Amplitude squared and the Frequency squared
91
Decibels
10*log(I/Io)20 to 60 decibels; ∆decibels/10 (40/10=4), 10^4=10,000 x louder
92
Wave speed
V= λf*Frequency NEVER changes medium-to-medium*Wavelength DOES change medium-to-medium
93
Beat frequency*When 2 waves w/ similar frequencies interfere
I F1-F2 I
94
Doppler effect
∆f/fs=v/c∆λ/λs=v/c*v=relative velocity*c=speed of wave (either 3x10^8 m/s for light OR 340 m/s for sound)
95
Harmonics: matching ends
λ=2L/n*gives all harmonics n=1,2,3,4 etcλ of 2nd harmonic= L *L=length of the string or pipe
96
Harmonics: non-matching ends
λ=4L/n*gives odd harmonics n=1,3,5 etc
97
Harmonic frequency
n*fundamental frequencyi.e. 1st harmonic=200 Hz, 2nd is 400 Hz etc.
98
Young's Double Slit Experiment
x=λL/dx=distance between fringesλ= wavelength of light usedd=distance between 2 slitsL=distance between the "double slit" and the screen
99
Index of refraction
n= c/v"n" of 1.5 for n simply tells us that the medium has some density, and is more dense than air (n=1). More dense=slower wave*faster medium= smaller index of refraction (n)
100
Index of refraction diagram formula
n1sinθ1=n2sinθ2The frequency will not change as the wave moves from one medium to another. We like to think of the frequency as the permanent “identifier” of a wave
101
Convex/converging lens
Usually= PRI*Object inside focal pt=NVU
102
Concave/diverging lens
Always= NVU
103
Focal length for mirrors
f=1/2r
104
Thin Lens equation (works for mirrors too)
1/f=1/di+1/do
105
Magnification
M=-di/do=hi/ho
106
Optical power
P=1/f
107
Two Lens system (binoculars, telescopes, etc): MAGNIFICATION
M=m1m2
108
Two Lens system (binoculars, telescopes, etc): POWER
P=p1+p2
109
Calculate pH
pH= -log[H+]
110
Calculate pOH
-log[OH-]
111
Relationship: pH & pOH
pH+pOH=14
112
Ionization of Water
Kw=[H3O+][OH-]=10^-14
113
Base Dissociation
Ka*Kb=Kw=10^-14
114
Henderson-Hasselbach equation
pH=pKa + log[A-]/[HA]
115
Nernst equation
E=E°- (0.06/n)*log[lower]/[higher]n=moles of electrons transferred (Fe 3+(aq)-->Fe (s)=3
116
Relationship between Free Energy and Chemical Energy
∆G°= -nFE°n=# moles of electrons transferred in balanced redox rxnF=Faraday's constant*+E°=negative ∆G=spontaneous rxn
117
Ideal Gas Law
PV=nRT
118
Combined Gas law
P1V1/T1=P2V2/T2
119
Partial Pressures
Ptotal=P1+P2+P3...
120
Effusion & Diffusion of gases
E1/E2= √MW2/√MW1Rate Gas 1/Rate Gas 2 [heavier]=√MW2[heavier]/√MW1
121
Vapor pressure w/ non-volatile solute
Vp=XVp°
122
BP elevation
∆T=(Kb)(m)(i)Kb=constantm=molalityi=# ions formed per molecule (CaCl2=3)
123
Freezing Point Depression
∆T=(Kf)(m)(i)Kf=new constant
124
Osmotic Pressure
π=iMRTi=# ions formed in solutionM=solute molarityR=gas constantT=K°
125
How CO2 is carried in the body
CO2+H2O-->HCO3- + H+
126
Electrical Power
P=IV
127
Energy (E) of a photon from its wavelength (λ)
E=hc/λ
