Thursday
April 24, 2014

Posts by Elena


Total # Posts: 4,312

Physical Science
convection.

Physical Science
convection.

phical science
Neutrinos are almost massless, travel close to the speed of light, and pass through matter almost undisturbed. Photons, on the other hand, have no mass, travel at the speed of light, yet are absorbed and/or reflected even by fairly sparse matter such as gasses. A photon has an...

physics
kx²/2 = mv²/2 v=sqrt(kx²/m)=sqrt(244•16•10⁻⁴/0.099) =...

physics
v₀ = 8.9 m/s m=4.1 kg R = 0.116 m μ=0.34 === F=ma F(fr)=μmg F=F(fr) ma= μmg a= μg=0.34•9.8=3.33 m/s² The torque M=Iε=(2mR²/5)•ε M=F(fr)•R= μmgR (2mR²/5)•ε= μmgR ε= 5μmgR/2mR²= ...

physics
kx²/2=mgh k=2mgh/ x²= 2•0.0961•9.8•0.591/(0.04754)²=...(N/m)

Physics
See my answer to a similar question below under related questions.

Physics
L₁= μ₀N²A/x₁ => x₁=μ₀N²A/L₁ L₂= μ₀N²A/x₂ => x₂= μ₀N²A/L₂ Δx=x₂-x₁=μ₀N²A{(1/L₁)–(1/L₂)}

Physics
Work=mgh==30•9.8•250 =... Power =mgh/t=30•9.8•250/30•60 =...

physics
a(centr)= mv²/R=0.036•36²/1.31 =…

Chemistry
0.25mol of CO are mixed with 0.90mol of H2 and heated to 950 degrees celcius in a 15L flask at equilibrium 0.190mol of H2O were present, what is the concentration of the other reactants and products at equilibrium and what is Kc

Physics 1
The law of conservation of linear momentum 0=mv-MV V=mv/M= 12•7.7/76.9 =1.2 m/s S=Vt=1.2•2•60 = 144.2 m

physics
ω=v/R ω =2πf v/R=2πf f=v/2πR= …

Physics (Algerbra-based)
a(centr) = a•cosα=14.3•cos30=… a(tang)=a•sinα=14.3•sin30=… a(centr)= v²/R, v=sqrt{a(centr) •R}=...

physics
The airplanes have the same speed -true The airplanes have the same velocity-false

Physics
http://www.physlink.com/education/askexperts/ae72.cfm

physics
C=Q/V C=εε₀A/d Situation I: The capacitor is disconnected from the battery, => Q=const (a) V=Q/C=Qd/εε₀A d₁=4d=> V₁=Q/C₁=Qd₁/εε₀A=4 Qd/εε₀A=4V (b) U=CU²/2=Q²d/2εε&...

PHYSICS
ΔKE=ΔPE=mgΔh=60•9.8•42 =24696 J

Physics 11th Grade
(a) cm₁(80-T)=cm₂(T-27) 2(80-T)=20(T-27) T=31.8 ℃ (b) λ= 330000 J/kg Q= λm=330000•0.1 =33000 J

Physics
Motion of the particle without deflection => F(el) = F mag) qE =qvB B=E/v=2607/6.81•10³=0.38 T For the second particle F=qE-qv₁B v₁=(F+qE)/qB= =1.8•10⁻⁹•3.72•10⁻¹²•2607}/ 3.72•10⁻¹²&#...

Physics
mv²/R=qvB R=mv/qB ΔR=R₂-R₁= =m₂v/qB - m₁v/qB= = v(m₂ - m₁)/qB)= =3•10⁵•(238-235)•1.67•10⁻²⁷/92•1.6•10⁻¹⁹•0.6= =1.7•10⁻⁴ m

Physics
ΔV=VB-VA =kq/r(B)-kq/r(A)= =kq{r(a)-r(B)}/r(A)•r(B). q = r(A)•r(B)•ΔV/k{r(a)-r(B)}= =(3.4-4.5)•45/9•10⁹•3.4•4.5 = = - 9.5•10⁻¹⁰ C

Phyics
ΔQ =4KCal=16747.2 J ΔQ=ΔU+W ΔU=ΔQ-W =16747.2-1000=15747.2 J

physics
ΔPE=A= q •Δφ Δφ= A/q=6.7•10⁻³/1.85•10⁻⁴=36 V

Physics
h= vₒ²•sin²α/2•g = =L•g•sin²α/2•g•sin2α= = L•sinα/4•cos α= =L•tanα/4

Physics
The voltage induced around the Al ring is ΔV=NΔΦ/Δt=Δ(0.5•B•A) /Δt = =0.5•A •ΔB /Δt. B =μ₀nI, ΔB /Δt= Δ(μ₀•nvI)/ Δt, ΔB /Δt= μ₀•n•ΔI/ ...

Physics
F=mg=100•9.8=980 N

Physics
C=q/U C=εε₀A/d q=CU= εε₀AU/d A) q1= εε₀A4V/2d= 2 εε₀AV/d B) q2 = εε₀2A2V/d= 4 εε₀AV/d max C) q3 = εε₀2A V/2d= εε₀AV/d D) q4 = εε₀A V/...

Physics
KE= m•v²/2 => v²= 2•(KE)/m a=v²/2•s =2(KE)/2•m•s = KE/m•s m•a=e•E E= m•a/e = m•KE/e•m•s = KE/e•s = =250•1.6•10⁻¹⁹/1.6•10⁻¹⁹•0.2 = 1250 V/m

Physics
A) 2ma=F-2T = > a=(F-2T)/2m = (12000-2•2100)/2•700 = 5.57 m/s² s=v²/2a = 40²/2•5.57 =143.6 m. B) T₁=ma +F(fr) =700•5.57 + 2100 =5999 N

physics
Angular magnification M= - F(objective)/F(eyepiece) F(objective)=1/1.2 = 0.833 F(eyepiece) = -1/220= - 0.0045 M= 0.833/0.0045 = 185

Physics 11th grade 3
1) F=ma => a=F/m = 75/17 = 4.4 m/s² s=v²/2a=3.75²/2•4.4=1.6 m 2) p= mv=0.18•3.75 =... 3) Impulse =mv=0.18•3.75 =... 4) Q=mcΔT=2•2060•20 = ...

physics
Rate of cooling R= ΔT₁/t₁=(80-50)/5=6 degr/min t₂= ΔT₂/R=(60-30)/6=30/6=5 min

physics
F(hor) =Fcos45 F(vert) =Fsin45

physics
F=ILB I=F/LB

physics
h=gt²/2 t=2h/g=2•0.63/9.8 =0.13 s. L=vt=0.3•0.13 = 0.039 m

Physics
γ=(i+2)/i=5/3=1.67 W=νRT₁ /(γ-1)}•{1-(V₁/V₂)^(γ-1)} = ={p₁V₁/(γ-1)}•{1-(V₁/V₂)^(γ-1)} = =(330000•1.2/0.67) •(1-0.5^0.67)= =591044.8•0.37 =2.2•10⁵ J

Physics ~please help me~
1a) W1=W2 = mgh 2a) P1 > P2 , mgh/25 >mgh/35 2) W=Fs=80•10 =800 J

physics
I=(0.73/2)²(4+3+5+2) = 1.87 kg•m² M=Iε=1.87•0.63 =1.175 kg•m

physics
http://answers.yahoo.com/question/index?qid=20090308072337AA3lVRt

Check my physics
OK

PHYSICS
mgh=mv²/2 v=sqrt(2gh)=...

PHYSICS
v(fin)=v₀=20 m/s

PHYSICS
mgh₁-mgh₂=mv²/2 h₂=h₁-v²/2

PHYSICS
Simbol - Arial Unicode MS http://www.alanwood.net/unicode/fonts.html

PHYSICS
Q=ΔKE=mv²/2

PHYSICS
F=ma=mv²/2s v=sqrt(2Fs/m)

PHYSICS
W=kx²/2

PHYSICS
mgh=mv²/2 v=sqrt(2gh)=...

physics
Q=W=F(fr)s=μNs=μ•mg•s =…

physics
α=ΔL/L•ΔT α=3.6•10⁻⁵/3 ΔL = 3.6•10⁻⁵•17• (5-100)/3 = = -0.05814/3=0.01938 m

physics
α=ΔL/L•ΔT ΔL = α• L•ΔT=3.6•10⁻⁵•17• (5-100) = = -0.05814 m

physics
The time that the bullet spends in the building t=x/v(0x) =7/340 =0.02 s. The vertical displacement of the bullet in the building y= 0.56 m. The vertical component of the velocity of the bullet as it passes through the window is v(y) = (y- gt²/2)/t = y/t - gt/2= =0.5/0.02...

Physics
h= vₒ²•sin²α/2g, Solve for vₒ

Physics
T=F/cosφ =60/0.707 = =60/0.707 = 84.87 N

Physics
cos φ=15/40= 0.375 φ=68⁰ F=Tsin φ = 1000•sin68 =927 N

Physics
v₁= {+2m₂v₂₀ +(m₁-m₂)v₁₀}/(m₁+m₂) v₂={ 2m₁v₁₀ + (m₂-m₁)v₂₀}/(m₁+m₂)

Physics
L=v(x)•t => t=L/v(x) h=gt²/2 = gL²/2v(x)² v(x)= sqrt (gL²/2h)

physics
k=mg/x=2.5•9.8/0.0305 =803.3 N/m the natural frequency is ω =sqrt(k/m) = sqrt(803.3/2.5)=17.9 rad/s

physics
http://answers.yahoo.com/question/index?qid=20120417015851AAp5Qdo

physics
(a) W(grav) = 0 since there is no change in height between the initial point and point A. (b) W(grav) – mgh –mg(h/2) = mgh/2 (c) W(grav) mgh -0 = mgh (d) mgh/2 (e) mgh

Physics
I=ℇ/(R+r) R= (ℇ-Ir)/I= (7.9-0.88•1.37)/0.88 = … P=I²r = …

Physics
x=Asinωt v=dx/dt =Aω cosωt= Aω•sqrt(1-sin²ωt) = =ω•sqrt(A² - A² sin²ωt)= ω•sqrt(A² -x²) A=0.076 m x= 0.045 m ω =17.8 rad/s v= ω•sqrt(A² -x²)= …

physics
ΔKE=-ΔPE KE2-KE1= -(PE2-PE1) ΔKE= KE2-KE1= m(v/2)²/2-mv²/2= = mv²/8-mv²/2= - 3mv²/8, ΔPE= PE2-PE1= k•q1q2/r-0=ke²/r - 3mv²/8 = - ke²/r, r=8ke²/3mv²= ... k =9•10⁹ N•m²/C² e =1.6...

Physics please help!!
Kepler’s Third Law. The square of the period is proportional to the cube of the distance from the star: T²∼R³ If the distance is increased by 25, then T² is increased by 25³, which means T is increased by the sqrt(25³)=125.

Physics please help!!
http://answers.yahoo.com/question/index?qid=20091117133730AAqpbug

Physics
See the answer to a similar question below under related questions

Physics
Elongation of the spring is x=2.69 –(2.22+0.28) = 0.19 m mg= kx k=mg/x- 145/0.19=763.16 N/m

Physics
5T=68 => T=68/5=13.6 s λ=34.1 m v= λ/T f=1/T

Physics
v = sqrt(T/m₀) =sqrt(TL/m) λ =v/f => v= λf (λf)²=TL/m L=(λf)²m/T

Physics
I can't see your drawing but if there are no nods of standing wave between the ends λ =2L v = sqrt(T/m₀) λ =v/f => f=v/ λ

Physics
t = s/v =2.19/343 = 6.38•10⁻³s λ =v/f = 343/525 = 0.653 m N = s/ λ

Physics
f =f₀/(1-v/u) f₀=1390 Hz f=1430 Hz v/u=(f-f₀)/f= (1430-1390) /1430=2.8•10⁻² m/s v/u = 2.8%

physics
v1+v2=88+104 =192 km/h

Physics
Beat frequency f =| f1-f2| 242<f<288 f-242=26 288-f=20 f=268 Hz

physics
t=s/v=1/0.1•3•10⁸ =3.33•10⁻⁸ s. y=gt²/2=9.8•(3.33•10⁻⁸)²/2=5.44•10⁻¹⁵ m

Physics
f=80 Hz, V=150V, R=3200 Ω, C=3.5•10⁻⁶ F ω=2πf =2π•80=160π(rad/s) ω²=1/T² =1/(2π)²LC => L=1/(2π ω)²C= .... X(L) =ωL= ... X(C) =1/ωC= ... tan φ=(X(L) –X(C))/R = ...

Physical Science
1B 2C 3A 4C

Physics
T=F=mv²/R=mω²R ω=sqrt(T/mR) f=ω/2π

PHYSICS
T=F=mv²/R=mω²R ω=sqrt(T/mR) ω = εt t=ω / ε 2πN= εt²/2 N= εt²/4π

Physics
W=KE2-KE1=KE2 - mv²/2= =7.14 - 0.67•2.2²/2 = 5.52 J

physics
for springs connected in tandem 1/k=1/k1 +1/k2 => k=1200 N/m the stretch is x=mg/k=5.9•9.81/1200 =

Physics
The total charge Q=2q=2•3•10⁻⁶ C=6•10⁻⁶ C. The total area of two spheres A=4π(r₁²+r₂²) = 4π•149•10⁻⁴ m² q₁=QA₁/A= 6•10⁻⁶•4πr₁²/A=...

Physics
(a) C=εε₀A/d Energy=Q²/2C (b) C₁=εε₀A/2d=C/2 Energy=Q²/2(C/2)= Q²/C

Physics
r=0.15 m, E< E₀ The dielectric strength of air E₀ =3 •10⁻³ V/m E=q/4πε₀r² => q=4πε₀r²E = 4πε₀r²E₀= = 4π•8.85•10⁻¹²•0.15²•3 •...

Physics
E= - gradφ= = - {(δφ/δx)i̅+(δφ/δy)j̅ + (δφ/δz)k̅}= = 2yz• i̅ –(4z-2xz)• j̅–(4y-2xy)•k̅.

Physics
E= - gradφ= = - {(δφ/δx)i̅+(δφ/δx)j̅ + (δφ/δx)k̅}= = 2yz• i̅ –(4z-2xz)• j̅–(4y-2xy)•k̅.

physics
v=const => a=0 N =F(x)•cosα F(y)•sinα=mg+F(fr) F(y)=(mg+μN)/sinα F=sqrt(F(x)²+F(y)²)

Physics
L=vₒ²•sin2α/g, B. 45°

physics
http://en.wikipedia.org/wiki/Electric_power

Physics
ε₀=8.85 •10⁻¹² F/m ε=5.4 e =1.6•10⁻¹⁹ C A=4.50•10⁻⁹ m² d=1.08•10 ⁻⁸ m U=54.6•10⁻³V C=ε•ε₀•A/d C=q/U ε•ε₀•A/d =q...

PLEASE COULD SOMEONE HELP ME OUT Physics
Separation between two wires is b=2Lsinα=2•0.5•sin3⁰=5.23•10⁻² m The mass of 1meter of the wire is m₀=ρπd²/4=2700•3.14•(0.3•10⁻³)²/4=1.9•10⁻⁴ kg where ρ =2700 kg/m...

Physics ~really need help!~
2. v₁= {-2m₂v₂₀ +(m₁-m₂)v₁₀}/(m₁+m₂)= =(m₁-m₂)v₁₀/(m₁+m₂)= v₂={ 2m₁v₁₀ - (m₂-m₁)v₂₀}/(m₁+m₂)= = 2m₁v₁₀ ...

PLEASE COULD SOMEONE HELP ME OUT
Separation between two wires is b=2Lsinα=2•0.5•sin3⁰=5.23•10⁻² m The mass of 1 meter of the wire is m₀=ρπd²/4, where ρ is the density of Al The force between two wires (per 1 meter) is F=μ₀I²/2π...

Physics
B=sqrt{B(x)²+B(y)²} = … F=qvBsinα sinα=sin90=1 => F=qvB = …

Physics
Problem #60 http://drjj.uitm.edu.my/DRJJ/Lecture/PHY407/Sample%20problems%20Chap%2021%20Cutnell.pdf

Physics
The field of the wire has a magnitude B(wire) = µ₀•I/(2πd) = … B(wire)/B(hor) = tan11⁰ ==> B(hor) = B(wire)/ tan11⁰ =

physics
P =I²R R =ρL/A= ρL/πr² P =I² ρL/πr² r=sqrt(I² ρL/πP)=... L=2 m, I=23.8 A, P=2.6 W, ρ= 1.72 x 10 ⁻⁸ Ω

physics
R=R₁+R₂+R₃=1.17+2.84+3.65 =7.66 Ω I=U/R = 20.3/7.66=2.65 A P₁ =I²R₁=2.65²•1.17= P₂ =I²R₂=2.65²•2.84= P₃=I²R₃=2.65²•3.65=

Physics
I=317 A B=7.69•10⁻³ T B(wire)=B B(wire)=μ₀I/2πa =B a= μ₀I/2πB= =4π•10⁻⁷•317/2π•7.69•10⁻³=8.24•10⁻³ m

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