Wednesday
April 23, 2014

Posts by Elena


Total # Posts: 4,311

Finance
A company has identified the following investments as looking promising. Each requires an initial investment of $1.2 million. Which is the best investment? a)a perpetuity that generates a cash flow at the end of year 1 of $100,000, has a growth rate of 1.25%, and a cost of cap...

Physics 1
λ =2L=2•0.5 = 1 m v= λ•f=1•261.6 = 261.6 m/s v = sqrt(T/m₀)= =sqrt(T•L/m) v²= T•L/m T= v²m/L=261.6²•3.8•10⁻³/0.5=520.10 N

physics
α= β => α + β=2 β =120⁰ β=60⁰

Physics
v₂=v₁/2, m₂=2m₁. p₁= m₁v₁, p₂=m₂v₂=2m₁•v₁/2= m₁v₁=p₁. KE₁=m₁v₁²/2, KE₂=m₂v₂²/2=2m₁ •v₁²/4•2= m₁v₁...

Physics
m₁v =(m₁+m₂)u u= m₁v/(m₁+m₂)=2•22/(2+7)=4.9 m/s

Physics
v=gt p=mv=mgt

Physics
FΔt=Δp= mΔv

Physics
0= MV - mv V=mv/M= 10•420/350 = 12 m/s

Physics
KE=PE+W(fr) mv²/2 = mgh +µmgcosα = = mgdsinα +µmgcosα, d= {v²/2 - µ gcosα}/gsinα

physics urgent please asnwer it i m begging u
I=j(x)A evB(z) =eE(y) E(y)=vB(z) neAv =j(x)A E(y) = j(x)B(z)/ne Constant of proportionality (Hall coefficient) = 1/ne=m³/C = m³/A•s

physics
W=ΔKE =mv₂²/2 - mv₁²/2 =m (v₂²/2 - v₁²/2) m= W/(v₂²/2 - v₁²/2)=…

physics
PE = mgh m=PE/gh= 800/6•9.8= 13.61 kg

physics
λ=c/f f₁=c/λ₁=3•10⁸/320•10⁻⁹ =9.375•10¹⁴ Hz f₂=c/λ₂=3•10⁸/280•10⁻⁹ =1.071•10¹⁵ Hz

Physics
T=273+22=295 K radiant emittance R radiant emittance of the black body R* Stefan-Boltzmann law R*=σT⁴ Stefan-Boltzmann constant σ =5.67•10⁻⁸ W•m⁻²•K⁻⁴ R= =kR*=kσT⁴ E=RAt =kσT⁴At E₁=R&...

Physics
Q/t=q= k•A•ΔT/Δx ΔT=q•Δx/k•A = = 250•1.7•10⁻³/0.2•1.8=1.18 K

Physics
L=ℏ √l(l+1) =√l(l+1)• h/2π l= n-1 => l=0, 1, 2, 3,4. L(max) = √(4•5) • 6.63•10⁻³⁴/2π=4.72•10⁻³⁴ kg•m²/s L(min)= 0

Physics Need help plz
The uncertainty in speed Δv = 0.22 m/s Δp•Δx =h/4π Δmv•Δx =h/4π Δv•Δx =h/4πm Δx= h/4π•m •Δv= =6.626•10⁻³⁴/4π•1900•0.22=1.26•10⁻³⁷...

Physics
Its incorrect. and you shut up so calles i am awesome

Physics
t₁=250/9 – 250/7 = 63.5 s t₂ = 500/8 = 62.5 s Δt=t₁-t₂=63.5 – 62.5 =1 s.

physics
mgh= mv²/2 v=sqrt(2gh)

physics
Work/time = Power = Force x speed The force is exerted on the bicycle to maintain the constant speed is F=P/v=400/10 = 40 N

physics
v=const => net force =0

physics
centripetal acceleration a= v²/R= = 4/0.5=8 m/s² centripetal force F= mv²/R= =0.05•4/0.5=0.4 m/s²

physics
centripetal acceleration a= mv²/R= =0.05•4/0.5=0.4 m/s²

Physics
Pb = lead

physics
Please can you tell the numerical value

physics
Tsinθ = mv²/R Tcosθ = mg tanθ=v²/Rg

physics
ma = Tsinθ mg= Tcosθ a/g =tanθ => a=g• tanθ

Physics
L=2.51•10⁻⁶ H x=1.17 m z=? L=μ₀N²A/z N=x/2πr => r= x/2πN => A=πr²=πx²/4π²N² L=μ₀N²A/z= μ₀N²πx²/4π²N²z= = μ₀x²/4z z= _...

chem (boyles and charles law)
p₁ =1.2 atm = 121590 Pa V₁= 1 L=10⁻³ m³ V₂=0.5•10⁻³ m³ p₁V₁=p₂V₂ p₂=p₁V₁/V₂

CRC
p₂=p₁T₂/T₁ p₁=675 torr = 89992.35 Pa T ₁=273+28 =301 K T₂ = 273+ 91= 364 K

Physics
E₃ = - E₁/n²= - 24.8/9 = - 2.76 eV

Physics
covalent bond

Physics
T•sin60•L=2450•sin30•0.39L +5000•sin30•L T•sin60=(2450•0.39 +5000)•sin30 T=(2450•0.39 +5000)•sin30/sin60=...

physics
mv=(m+M)u u =mv/(m+M), (m+M)u²/2=(m+M)gh. u=sqrt(2gh). mv/(m+M)= sqrt(2gh) v= (m+M)•sqrt(2gh)/m

Physical Science
#4

chem (boyles and charles law)
T₂=V₂T₁/V₁

chem. mix of boyles and charles law
V₂=T₂V₁/T₁ 1 atm = 101325 Pa 1 L = 10⁻³ m³

chemistry (charles law)
V₂=T₂V₁/T₁ T₁=303 K T₂=273 K

chemistry (charles law)
V₂=T₂V₁/T₁

physics
Given data: 1st rod: L₁, T₁, x₁, a => A₁=a²; 2nd rod: L₂, T₂, x₂, d => A₂= πd²/4; Hook’s Law for rods: σ=Eε T/A = E•x/L, 1st rod: T₁/a²= E•x₁/L₁, 2nd rod: 4T...

Science
m=D•V

Physics
m=39.0 kg s=4.5 m, F=135 N, μ=0.3 (a) W(F) = Fs (b) ΔU= W(fr) = μmgs (c) W(N) = 0 (d) W(mg) = 0 (e) KE=W(F) –W(fr) =Fs - μmgs (f) KE=mv²/2 v= sqrt(2•KE/m)

physics
The sums of torques respectively the edges of the board are: W•x-400•2 = 0 W• (2-x) -700•2=0 W•x=800 2W-W•x -1400 = 0 2W-800-1400=0 W=1100 N x=800/W =0.73 m

physical science
(A)tetrahedral This distorted tetrahedral arrangement is call bent. http://www.ausetute.com.au/shapemol.html

physics
h=s•sinα=v•t•sinα=1.5•21•sin30=15.75 m

physics
p=sqrt{p(x)²+p(y)²} = = sqrt{(10•9) ² +(20•12)²}=256.32 kg•m/s v= p/(m₁+m₂) =256.32/30 =8.54 m/s

physics
k =9•10⁹ N•m²/C² r=0.18 m q₁= 5•10⁻⁹ C q₂ = - 2•10⁻⁹ C PE= k•q₁•q₂/r = ...

physics
φ =198t-24t²-2t³ (a) ω=dφ/dt=198 -48t-6t², ω=0 => 198 -48t-6t²=0, 6t²+48t-198=0, t²+8t – 33 =0, t= -4±√(16+33 ) =-4±7, t=-11 (impossible), t=3 s. (b) ε=dω/dt= - 48 -12t. t=3 => ε=-...

Physics
F=qE=eE => E=F/e=3•10⁻¹⁵/1.6•10⁻¹⁹= 1.875•10⁴ N E=Δφ/Δx= Δφ/d => Δφ=Ed=1.875•10⁴•0.2=3.75•10³ V

Physics
mg=kx x=mg/k=2.35•9.8/1.64•10³=0.014 m

Physics
F=k•q₁•q₂/r², k =9•10⁹ N•m²/C², q₂ = F•r²/k•q₁ = 1.8•0.3²/9•10⁹•6•10⁻⁶ = =3•10⁻⁶ C = 3 μC Due to the attraction of the charges qS...

Physics
F=k•q₁•q₂/r²= k•q²/r² q=sqrt{ F•r²/k}=sqrt{7•10⁻⁹•(3.2•10⁻¹⁰)²/9•10⁹}=2.82•10⁻¹⁸C

Physics-- please help me finish!!
m₂g=kx k= m₂g/x=0.363•9.8/0.026 = 136.8 N/mþ T=2π•sqrt(m₁/k) = =2π•sqrt(1.4/136.8)=0.64 s

physics
L=Iω=mR²ω =0.5•1.45²•1.5 = 0.29 kg•²/s

physics
fluorine gas F₂=> μ = 36 g/mol =36•10⁻³ kg/mol, m= 0.076 kg, V=1.5 L = 1.5•10⁻³ m³, t= -37℃ = 236 K, pV=mRT/ μ => p =mRT/ Vμ =0.076•8.31•236/1.5•10⁻³•36•10⁻³= =...

Physics SI unit
Newton

physics
F₁=mv²/R₁ F₂=mv²/R₂=mv²/2R₁=F₁/2

Physics
B=sqrt{B(y)²+B(z)²} = =sqrt{0.5²+0.67²} = 0.836 T, F=qvBsinα, sinα=1, F=qvB=31•10⁻⁶•62•0.836=1.6•10⁻³ N. Vector B makes an angle β with z-axis: tanβ =B(y)/B(z) =0.5/0.67=0.746, β=36.7° ...

physics - stopping distance
The reaction time is t =x/v=7.5/10 = 15/20 =22.5/30 = 0.75 s. The reaction distance for v=25 m/s is x=vt=25•0.75 = 18.75 m. The acceleration is a=v²/2s=10²/2•5=20²/2•20=30²/2•45=10 m/s² The breaking distance for v=25 m/s is s= v...

physics
F=ILB B=F/IL

physics
mgh=mv^2/2, v=sqrt(2gh) = ...

physics
F=qvB =evB v=F/eB=...

physics
engine’s efficiency=A/Q =417/848=0.49 or 49%

Physics
A) L=λ/2=v/2f B) L=λ/4=v/4f v is the speed of sound

Physics
φ=ω₀t±εt²/2 ω=ω₀±εt ω=2πn ω₀=2πn₀=0 φ=εt²/2 2πn= εt ε=2πn/t φ=εt²/2=2πn t²/2t= πn t=3.14•30•5=...(rad)

Physics
mg(H+h)=mv²/2 v = sqrt{2g(H+h)}

Physics
p=ρgh+p₀ = 1025•9.8•10300+101325 =103564825 Pa F=pA=pπr²=103564825•π•0.13²=5.5•10⁶ N

Science/DUE TODAY
http://wiki.answers.com/Q/What_3_changes_polar_bears_would_need_to_change_to_live_in_the_desert

Quantum Physics
1/λ =R(1/n² - 1/m²) = =1.1•10⁵(1/1²-1/∞) λ = 9.1•10⁻⁶ m

Math
10/(3x) + 4/3 = (7+x)/2x 20+8x=21+3x 5x=1 x=1/5

Physics Eletric fields and coulomb's law)
E=ke/r², r=sqrt(ke/E) = = sqrt(9•10⁹•1.6•10⁻¹⁹/2.02•10⁻⁷)= =8.44•10⁻²m

Math PLEASE HELP!
What is the base of your logarithms? If it is common logarithm logx=log₁₀x=3.5829 => x=10³•⁵⁸²⁹=3827.366 If it is binary logarithm logx=log ₂x=3.5829 x=2³•⁵⁸²⁹=11.983. If it is natural logar...

physics
The gravitational constant G =6.67•10⁻¹¹ N•m²/kg², h=100000 m m=1040 kg Earth’s mass is M = 5.98•10²⁴kg, Earth’s radius is R = 6.37 •10⁶ m. (a) F =G•m •M/(R+h)² (b) a= G• M/(R+h)²...

science
http://en.wikipedia.org/wiki/Thermal_conduction

Physics
B=μ₀I/2πb=1.25664•10⁻⁶•1.24/2π•0.436 =5.69•10⁻⁷ T

physics
F=qE=eE=1.6•10⁻¹⁹•341•10⁵=5.456•10⁻¹² N

Physics
cosα=1, ℇ=ΔΦ/Δt = N•Δ(B•Acosα)/Δt= =N•A•ΔB/Δt, ℇ=I•R, N•A•ΔB/Δt= I•R, I= N•A•ΔB/Δt•R= =347•0.28•2.4/0.31•49 = 15.35 A

physics
cosα=1 ℇ=ΔΦ/Δt = N•Δ(B•Acosα)/ Δt= =N•A•ΔB/Δt ℇ=I•R N•A•ΔB/Δt= I•R I= N•A•ΔB/Δt•R= ...

PHYSICS!!!!...PLEASE HELP
v=const => mgsinα=F(fr) = μN= μmgcosα sinα= μcosα μ=tanα

physics
mgh=kx²/2 x=sqrt(2mgh/k)

Science
An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving the atom a net positive or negative electrical charge.

Physics
The object located between F and 2F => the image will be located beyond the 2F point on the other side of the lens. It is real, inverted and its dimension is larger than the object demension. d₀ - object distance d₁ - image distance f- focal lenth 1/d₀ +1/...

Physics *Electrical Scientist* please help me!!!
http://www.tutorvista.com/science/jj-thomson-atomic-theory-0 http://en.wikipedia.org/wiki/Cathode_ray_tube

calculus
t=∛x =x^(1/3) => y=3x^5 = 3x^(5/3). dy/dx =3•(5/3)•x^(2/3) = =5 •125^(2/3)=525=125

Physics
d₀ - object distance d₁ - image distance f- focal lenth 1/d₀ +1/d₁ =1/f, 1/d₁ =1/f - 1/d₀ = = (d₀-f)/ d₀•f, d₁=d₀•f/(d₀-f)= =0.4•0.15/(0.4-0.15)=0.24 m, 0.03/0.4 =h/ d₁ , h= d₁•0....

Physics
mgsinα=F(fr) = μN= μmgcosα sinα= μcosα μ=tanα

calculus
s= 189t- t³ v=ds/dt = 189-3t² t=0 = > v=189 m/s. 189-3t² = 0 t=√(189/3) =√63 = 7.94 s. s=189 t- t³= =189(7.94) -7.94³=1000.1 m a=dv/dt =d(189-3t²)/dt= - 6t t=8 => a= - 6•8 = - 48 m/s²

physics
I=2mR²/5 ω=2π/T KE= Iω²/2

Physics
m₁gh= m₁v₁₀²/2 => v₁₀=sqrt(2gh) m₂gh= m₂v₂₀²/2 => v₂₀ =sqrt(2gh) m₁v₁₀ - m₂v₂₀= - m₁v₁ + m₂v₂ v₁= {-2m₂v₂₀...

Physics
C)λ, ν, and 100E

calculus (gr 12)
f(x) = 2x³+4x²-5x+8 f′(x) =6x²+8x-5 f′(-2) = 2(-4) ² +8(-2) -5 = 11

calculus
f(x) =x⁴-3x f′(x) = 4x³ -3 => f′(3) = 4•3³ -3= 105

calculus (gr 12)
s= 189t- t³ v=ds/dt = 189-3t² t=0 = > v=189 m/s. 189-3t² = 0 t=√(189/3) =√63 = 7.94 s. s=189 t- t³= =189(7.94) -7.94³=1000.1 m a=dv/dt =d(189-3t²)/dt= - 6t t=8 => a= - 6•8 = - 48 m/s²

physics
X: ma=Fcosα-F(fr) Y: 0=-mg+N+Fsinα =>N=mg-Fsinα F(fr) = μN=μ(mg-Fsinα) ma= Fcosα- μ(mg-Fsinα) a = { Fcosα- μ(mg-Fsinα)}/m

physics
S=(v-v₀)•t=(2-1) •3•60= 180 m

physics
F₁=k•q₁•q₂/r₁², F₂=k•q₁•q₂/r₂², F₁/F₂=k•q₁•q₂•r₂² / k•q₁•q₂•r₁², F₂= F₁• r₁²/r S...

Physics
T₁=2πsqrt(m₁/k) T₂=2πsqrt(m₂/k) T₁/T₂=sqrt{m₁/m₂} T₂=T₁/sqrt{m₁/m₂}= 2.8 s

Physics
λ=v/f =3•10⁸/6•10¹⁶=5•10⁻⁹ m

Physics :)
Angular acceleration= torque/moment of inertia

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