Friday

November 21, 2014

November 21, 2014

Total # Posts: 4,334

**Math**

the average of five numbers is 16. Suppose 10 is added to five numbers. What is the average of the six numbers?
*October 12, 2014*

**chemistry**

Use activity coefficients to find the concentration of hydrogen ions in a solution of 90.0 mM butanoic acid and 0.05 M NaCl. The ionization constant of butanoic acid is Ka = 1.52 × 10-5. Take the size of C3H7COO– to be 500 pm. How do I calculate the ionic strength ...
*October 3, 2014*

**math**

two students are playing a math game . the object of the game is to make the least possible number by arranging the given digits inside absolute value bars on a card . in the first round , each player will use the digits 3,5,and7 to fill in the card. One student arranges the ...
*September 25, 2014*

**Law**

2. http://en.wikipedia.org/wiki/Diversion_program
*June 10, 2014*

**physics**

Here, u1 = 30 km/h t = 2 s u2 = 33.6 km/h a = (u2 – u1)/t a1 = (33.6 – 30)/2 = 1.8 ms-2 Similarly, a2 = (37.2 – 33.6)/2 = 1.8 ms-2 The acceleration of the vehicle is 1.8 ms-2
*June 10, 2014*

**MATH**

B. 5/51
*June 9, 2014*

**MATH**

I think it's B. The probabilities change every time a bill is pulled out. The probability of pulling out a 1 first is 5 out of 18 which is .227 then the probability of pulling out a 10 is 6 out of 17 because you don't replace the bill. since the events are independent ...
*June 9, 2014*

**MATH**

I think it's B. The probabilities change every time a bill is pulled out. The probability of pulling out a 1 first is 5 out of 18 which is .227 then the probability of pulling out a 10 is 6 out of 17 because you don't replace the bill. since the events are independent ...
*June 9, 2014*

**business**

This site will show you what you need http://www.opengroup.org/public/arch/p4/bus_scen/bus_scen.htm
*June 8, 2014*

**algebra**

This site shows you how to find terms of the sequence http://www.math-magic.com/sequences/next_term.htm
*June 5, 2014*

**I may fail the 8th grade?**

1. Take a deep breath. 2. I may be able to help. 3. post questions on your homework here and either ms.sue will help or me. BTW HELP we wont give you the answers but we will ensure help and explanations and you will get it right
*June 5, 2014*

**Biology**

A virus is a rudimentary biosystem that has some of the aspects of a living system such as having a genome (genetic code) and the ability to adapt to its environment. A virus, however, cannot acquire and store energy and is therefore not functional outside of its hosts. ...
*June 5, 2014*

**biology**

A capsid is the protein shell of a virus. It consists of several oligomeric structural subunits made of protein called protomers. A prion is an infectious agent composed of protein in a misfolded form.
*June 5, 2014*

**Psychology**

Read this and find your answer http://www.sirc.org/publik/drinking3.html
*June 5, 2014*

**Psychology**

What may ultimately make an abnormal behavior into a genuine mental disorder is if the behavior: 1. is maladaptive (harmful to self or others) 2. causes significant social impairment 3. causes significant occupational impairment 4. causes great personal pain and emotional ...
*June 5, 2014*

**biology**

The basic difference is their components. Viruses contain both nucleic acids (DNA or RNA) and a protein coat. Viruses cause infection by inserting their genetic material in a host cell. The host cell then replicates and reads the genetic material, making new viruses that ...
*June 5, 2014*

**Algebra**

there are 56 ways
*June 5, 2014*

**Algebra**

use the 8C3.now, can u evaluate the value of 8C3 ?.nCr = n!/r!(n-r)!it is the general formula of combination. also u have know about the "factorial", like 3! = 3 * 2 * 1 = 6 8C3, in this case knowed n=8 and r=3. by using the formula above, it can be 8C3 = 8!/3!(8-3...
*June 5, 2014*

**Measurment**

To answer this question, you'll need to find the surface area of the top of the container (which is a circle), along with the surface area of the side of the container.Note that the diameter of the container is given and is 6 inches; therefore, the radius is ... what? Note...
*June 5, 2014*

**english**

I think its either A. or C. but im not sure. Maybe A
*May 28, 2014*

**english**

In "A Man Called Horse," After his wife leaves him, Yellow Robe Behaves recklessly in battle because he A. would rather die than live with the bitterness he feels as a result of his lost pride B. is trying to gain membership in the society known as the foxes C. ...
*May 28, 2014*

**english**

I think its D
*May 28, 2014*

**english **

writers portray the personalities of characters A. only through revealing the characters private thoughts. B. through plot complication. C. only if the plot is not important to the story. D. through a variety of methods.
*May 28, 2014*

**7 grade math**

Thank you @Bobpursley!!
*May 27, 2014*

**7 grade math**

Consider two types of nonlinear equations. What unique quality does each possess and how does that quality cause the graph's unique shape? Name two unique examples of these shapes in real-world situations.
*May 27, 2014*

**URGENT Physics help**

F=kq₁q₂/r² q₂= F r²/kq₁= 7.2•10⁻²/9•10⁹•4•10⁻⁶= =2•10⁻⁶ C = 2μC Cpper rod is an electrical conductor; the others are insulators.
*May 7, 2014*

**Physics**

C=q/Δφ q=C Δφ
*May 7, 2014*

**engineering**

In the question I have some strenths and w/c ratios of some specimens and it is asking me about the range,molds?Also,How many specimens should be taken for each batch of concrete? This is a question before we learn it,so really have some understanding problems.
*May 4, 2014*

**engineering**

Hello guys.I got a homework and seem like I am stocked. a)What type of experiments should be done to find the relationship between the strength of concrete and water/cement ratio. b)what will be the range of the water/cement ratio? It would be great if you help.Thank you!
*May 4, 2014*

**Math**

To Damon: thank you so much for your help :))))))
*April 29, 2014*

**Math**

To Steve: I just copy that from my child's textbook as it is. Thank you for your great advice, I'll forward it to his math teacher.
*April 29, 2014*

**Math**

Hector has $450 and saves 20 per week. Tim has $1200and spends $30 per week.write a system equation for this situation
*April 29, 2014*

**Physics 194**

d•sinφ=kλ, tanφ=x/L. => d•x/L=kλ λ₁=dx₁/Lk λ₂=dx₂/Lk λ₁/λ₂=dx₁Lk/dx₂Lk= x₁/x₂ λ₂=λ₁x₂/x₁=630•0.21/0.26=508 nm
*April 25, 2014*

**Physics**

bsinφ=k λ sinφ=kλ/b, a) sinφ=1•630•10⁻⁹/0.020•10⁻³=0.0315 φ=1.8° b) sinφ=1•630•10⁻⁹/0.20•10⁻³=0.0035 φ=0.18° c) sinφ=1•630•10⁻⁹...
*April 25, 2014*

**physics**

a=ω²R, F(fr)=μN=μmg, ma =F(fr) => mω²R₁= μmg m(2ω)²R₂=μmg ω²R₁=4ω²R₂ R₂=R₁/4
*April 24, 2014*

**physics**

Imagine that F₂ is along the x-axis, F is along y-axis, and F₁ is directed to the “north-west”. The angle between F and F₁ is α. sin α = F₂/ F₁=1/2 α=30° Thus, the angle between F₁ and F₂ is 90°+30°...
*April 19, 2014*

**Physics**

W=mg
*April 18, 2014*

**physics**

1/λ₁ =Z²R[(1/n²) – (1/m²)] =2²•1.1•10⁷[(1/1²) –(1/3²)] λ₁=2.56•10⁻⁸ m 1/λ₂ =Z²R[(1/n²) – (1/m²)] =2²•1.1•10⁷[(1/2²) –(1/...
*April 17, 2014*

**physics**

E=5eV=8•10⁻¹⁹ J λ=h/p = h/sqrt(2mE) = =6.63•10⁻³⁴/sqrt(2•9.1•10⁻³¹•8•10⁻¹⁹)=5.5•10⁻¹⁰ m
*April 17, 2014*

**physics**

S=Energy per unit time/Area = Nhf/A= =4Nhc/πD²λ= =4•1.42•10¹⁸•6.63•10⁻³⁴•3•10⁸/π•(1.82•10⁻³)²•524•10⁻⁹= =2.07•10⁵ W/m² Electric ...
*April 17, 2014*

**physics**

(a) 1/do+1/di =1/F 1/di=1/F-1/do=1/48.5•10⁻³- 1/3.85•10⁸. di≃48.5•10⁻³m x/di=D/do x=D•di/do =3.48•10⁶•48.5•10⁻³/3.85•10⁸.= =4.38•10⁻⁴ m (b) 1/do₁+1/di₁...
*April 17, 2014*

**physics**

tan(α/2) =x/L => x=L tan(α/2) Coordinate of the second dark fringe is x=(2k+1)Lλ/d L tan(α/2)= (2k+1)Lλ/d d/λ =(2k+1)/tan(α/2)= (2•2+1)/tan3.6°=79.5
*April 17, 2014*

**Physics**

(i) h=gt²/2 t=sqrt(2h/g)=sqrt(2•10000/9.8)=45.2 s. (ii) v=800000/3600 = 222.2 m/s s=vt =222.2•45.2 =10044 m (iii) x=0 (since the horizontal speed of the cargo is constant)
*April 14, 2014*

**Physics**

The speed of sound at 20°C v=343 m/s s=vt=343•3=1029 m
*April 14, 2014*

**Physics**

If the detector (radar)is at rest and the source (moving car that reflects the sound)) is moving away from the detector, the observed frequency f is less than the actual frequency f₀. The speed of sound v =343 m/s f=f₀v/(v+V) V=v(f₀-f)/f =343•(1.5-1.4)&#...
*April 14, 2014*

**physics**

KE=mv²/2 v²= 2•KE/m a= v²/2s F=ma=mv²/2s= 2m•KE/2s m= = KE/s=10/0.005 =2000 N
*April 14, 2014*

**physics**

v₁ =910 m/s m₂=1000 kg v₂=10000 m/s u= 1000 m/s m₁=? (m₁+m₂)u = m₁v₁ +m₂v₂ m₁=m₂(v₂-u)/(u-v₁)= =1000(10000-1000)/(1000-910) = 100000 kg
*March 25, 2014*

**Trigonometry**

find sin2x, cos2x, and tan2x if sinx= -2/sqrt 5 and x terminates in quadrant III
*March 25, 2014*

**physics**

v=v₀+at = 10.5+(4.4•4.2) = 28.98 m/s
*March 25, 2014*

**Phyics**

1. x: ma=mg•sin α –F(fr) y: 0=-mg•cos α +N ma=0 0= mg•sin α-μN= = mg•sin α-μ•mg•cos α tan α = μ =0.4 α=arctan0.4 =21° 2. ma=mg•sin α – μ₁mg•cos α a=g&#...
*March 20, 2014*

**Physics**

The blocks move with the same acceleration ‘a’ F(fr)= μN m₁g=W₁ => m₁=W₁/g= 77/9.8=7.86 kg m₂g=W₂ => m₂=W₂/g= 114/9.8=11.63 kg x: m₁a=m₁g•sin α -μ₁N₁-T y: 0=-m₁g...
*March 20, 2014*

**physics**

1. PE=KE PE=mgh=mg•s•sinα KE=mv²/2 mg•s•sinα=mv²/2 v=sqrt(2g•s•sinα) = =sqrt(2•9.8•1.8•sin22°)=3.64 m/s v=at => a=v/t s=at²/2= vt²/2t=vt/2 t=2s/v=2•1.8/3.64 =0.99 s 2. t₁=2t=0.99...
*March 20, 2014*

**Science**

p=mv=20•5 =100 kg•m/s
*March 20, 2014*

**Physical Science**

(60 W•24hours •30 days)/1000=43.2 kW•h 43.2•0.1$=4.32$
*March 20, 2014*

**Physics**

T=ma=mv²/L m=TL/v²
*March 20, 2014*

**Physics**

An angular speed ω=v₁/R₁=v₂/R₂ v₁/v₂= R₁/R₂=9.8/6.6 =1.48
*March 20, 2014*

**Physics**

T=ma=mv²/R=1.9•2.8²/2.3= 6.48 N
*March 20, 2014*

**Physics**

B= μ₀•I/2π•d= μ₀•q•t/2π•d q=2π•d•B/ μ₀•t= =2π•28•7.3•10⁻⁵/4π•10⁻⁷•2.2•10⁻³=4.64•10⁶ C
*March 20, 2014*

**Physics**

L is the length of the solenoid N is the number of turns d is the diameter of the wire r is the radius of the solenoid (of the turn) Resistance R=ρx/A=4ρx/πd² ρ=1.6•10⁻⁸ Ω•m μ₀=4π•10⁻⁷ H/m U...
*March 20, 2014*

**MATH**

explain how to construct a perpendicular bisector
*March 12, 2014*

**Science**

the process in which body cells are duplicated in order to grow and repair body tissues is called
*March 6, 2014*

**Physics**

p=mv
*February 27, 2014*

**physics**

W=mg
*February 27, 2014*

**physics**

mg =ma =mv²/R v=sqrt(gR)=sqrt(9.8•0.6)=2.4 m/s
*February 26, 2014*

**Physics**

Work W=F•s•cosθ cosθ= W/F•s= 43/60•2=0.358 θ=69° ma=Fcos θ a=v²/2s= 2.7²/2•2 = 1.82 m/s² m= Fcos θ/a=60•0.358/1.82 =11.8 kg
*February 26, 2014*

**Physics**

Q=mλ=6.68•335000=2.24•10⁶ J
*February 26, 2014*

**Physics**

F =G•m₁•m₂/R² the gravitational constant G =6.67•10⁻¹¹ N•m²/kg², F=6.67•10⁻¹¹•0.005•10/0.25=...
*January 22, 2014*

**Physics**

mgsinα=F sinα=F/mg=3.06x10^6/1.39x10^4 =0.022 α= 1,26 degr
*January 13, 2014*

**Physics**

T=1/f=1/2= 0.5 s
*January 13, 2014*

**physics**

h=gt²/2 t=sqrt(2h/g) x=v(x) •t => v(x) =x/t=x/sqrt(2h/g) = =8.3/sqrt(2•4.3/9.81)=8.9 m/s
*January 11, 2014*

**Physics**

v= v₀+at=30.55-0.805•20=14.5 m/s =14.5•3600/100=52.04 km/h
*January 11, 2014*

**Science question**

Coal is solid, the other substances are liquids and gas Answ A http://library.thinkquest.org/3646/earth/resources/fosfuels.html
*January 10, 2014*

**Physics Classical Mechanics Help ASAP**

http://cnx.org/content/m14614/latest/
*January 10, 2014*

**physics**

mgh=mv²/2 v=sqrt{2gh} =sqrt{2•9.8•2.9} =7.5 m/s v(fin)=v-at v(fin)=0 a=v/t x=vt -at²/2=vt/2 mv²/2 =W(fr) = F(fr) •x => F(fr)= mv²/2x = 2mv²/2 vt=mv/t = =70•7.5/0.58 = 905.2 N
*January 10, 2014*

**physics**

a) W+Fx =80•0.882=70.56 J b) W=KE =mv²/2 v=sqrt(2W/m) = sqrt(2•70.56/15)=3.07 m/s c) KE=W(fr) =F•x F=W(fr)/x=KE/x=F/x = 70.56/0.045=1568 N
*January 9, 2014*

**physics**

W/A =Y(ΔL/L) ΔL=W•L/A•Y= =mg•L/πr²•Y
*January 7, 2014*

**Physics help quick!**

The force is directly proportional to 1/r2 where r is the distance. 19 AU 9.8 N/kg
*January 7, 2014*

**science**

q=K(ΔT/Δx)WL= =0.84•19•0.9•1.5/0.004 =5386.5 W
*January 7, 2014*

**physics**

Weight on one foot =480/2=240 N Pressure under her soles =Weight/area = =240/area of one sole
*January 5, 2014*

**physics**

240N
*January 5, 2014*

**physics**

PE=W(fr) kx²/2=μmgd d= kx²/2μmg= =124•2.1²/2•0.7•7•9.8 =5.7 m
*January 5, 2014*

**physics**

m₁v₁-m₂v₂=-m₁u₁+m₂u₂ u₂= (m₁v₁-m₂v₂+m₁u₁)/m₂= =(1250•30-2000•25+1250•10)/2000 = 0
*January 5, 2014*

**Need help World Geography**

1.B 2.D http://en.wikipedia.org/wiki/Slum
*January 4, 2014*

**Physics**

A) W=∫F•dx=-∫kx•dx (limits ↓0↑x) =kx²/2 or ΔW=F•Δx =-kx •Δx, W=ΣΔW= Σ(-kx•Δx)= =- kx Σ{(0-x)/2}= kx²/2 B) W= kx²/2=80•0.35/2 =14 J
*January 3, 2014*

**physics**

h=gt²/2 => t=sqrt(2h/g) =sqrt(2•73/9.81) =3.86 s v(y) = gt = 9.81•3.86 =37.87 m/s v=sqrt{v(x)²+v(y)²} =sqrt{37.87²+40²}=55.08 m/s p=mv=Pv/g =177•55.08/9.81 =993.85 kg•m/s tan α =v(y)/v(x) =37.87/40 =0.947 α=arctan0.947...
*January 3, 2014*

**AP Calculus AB**

y´=3(cosx)²(-sinx) -3(sinx)²cosx= = - 3 sinx cosx(cosx+sinx)
*January 3, 2014*

**Need help World Geograpy**

3A 6C 7C 10B 12C 13D 17D 18B 20B
*January 3, 2014*

**Physics**

P=Fv=mav a=P/mv=4300/900•13.8=0.35 m/s²
*January 2, 2014*

**physics**

PE=KE mg(H+h) =mv²/2 v=sqrt{2g(H+h))
*January 2, 2014*

**Physics**

P=Fv=mav a=P/mv=4300/900•13.8=0.35 m/s²
*January 2, 2014*

**Physics**

Q =q•W•L•t= 1380•1000•1300•12•3600= =7.75•10¹³ J Q=cmΔT ΔT= Q/cm = Q/cρV=7.75•10¹³/4180•1000•1000•1300•300= =0.048 K
*January 2, 2014*

**Physics**

m₁=36 kg, c₁= 880 J/kg•K, m₂=4 kg, c₂=387 J/kg•K Q=m₁c₁ΔT + m₂c₂ΔT = = ΔT(m₁c₁ + m₂c₂). ΔT= Q/(m₁c₁ + m₂c₂)= =60000/(36•880+4•387) = 1.8 K
*January 2, 2014*

**Physics**

a=dv/dt= -b+2ct =-0.31+2.1•10⁻³•36= =-0.2344 m/s² P=Fv=ma•v = 1264•0.2344•18.36 = 5439.7 W
*January 2, 2014*

**physics**

Y=2•10¹¹ Pa ω=2πf =2π•2=4π rad/s. ma=T-mg m ω²R =T – mg T=m(ω²R+g) =m(16π²R +g)=… T/A =Y•ΔL/L ΔL=TL/AY =…
*January 2, 2014*

**physics**

V=53•10⁶ ft³=1.5•10⁶ m³ h=45720≈46000 m The density of the air ρ=2•10⁻³ kg/m³ The buoyant force is F=mg= ρVg=2•10⁻³•1.5•10⁶•9.8 =29400≈ 30000 N Answer (d) M=800 kg m...
*January 1, 2014*

**Physics**

W(horse) =W(fr) =μNs= μmgs m=W/ μ gs= 8000/0.25•9.8•62=52.7 kg If the rope is horizontal and v=const => T= F(fr) = μmg=0.25•52.7•9.8 =129 N
*January 1, 2014*

**Physics 221**

E=Δφ/Δx PE->W(work of electric field) -> KE W=e•Δφ=e•E•Δx KE= mv²/2 mv²/2= e•E•Δx v=sqrt{2•e•E•Δx/m}= =sqrt{2•1.6•10⁻¹⁹•1000•0.001/9.1•10&#...
*December 31, 2013*

**Physics**

mv²/2 = kx²/2 +μmgs ==== W(spring) = kx²/2=... E(fr) = μmgs=... v =sqrt{kx²/m +2μ gs}=...
*December 31, 2013*

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