Thursday

March 26, 2015

March 26, 2015

Total # Posts: 37,658

**Physics**

hf=hi-1/2 g t^2 -300=-4.9 t^2 solve for time t.
*March 26, 2015*

**chemistry**

I have no idea what the reaction is. I am surprised your chem teacher has not counseled you yet on the math issue.
*March 26, 2015*

**Physics**

vf=vi+gt =20-9.8*2 m/s If you round to ten, vf is zero. Why do folks use 10m/s^2 as g? Nowhere on the Earth is it that value. Why not use 3.0 as PI?
*March 26, 2015*

**CHE107**

There are avag number of molecules in a mole, but in NaCl, there are two atoms per molecule, so Number atoms: avagNumber* 2
*March 26, 2015*

**Business**

I am not certain what an "executive administrator" is, or what she does. If she were the boss of the managers, she ought to tell them to either negotiate, or let her do it. Or fire them.
*March 26, 2015*

**Geometry B**

yes, if it really a kite (geometry) shape.
*March 23, 2015*

**physics**

and the distance it has went is 1/2 vf*time
*March 23, 2015*

**physics**

Vf^2=2ad vf=at so (at)^2=2ad a=2d/t^2=2*.65/(.5)^2 Now that you know a, vf=at when t is three
*March 23, 2015*

**critical thinking**

examples: A. were you hit? B. you hit me silently. C stop hitting me D Blue Chickens accuse? D is the wrong form. We Accuse blue chickens.
*March 21, 2015*

**science**

initial difference in A and B=46C four min later they are 16C apart, they have went 16/46 (about 1/3 the way) initial difference in C and D are 46C four min later they are 10C apart, they have went 10/46, or about 1/5 they way. C and D are exchanging heat much more slowly than...
*March 21, 2015*

**science**

I think you need to look at the rate of cooling, ie,how fast they are changing. Exactly what is that k in the exponent?
*March 21, 2015*

**science**

Nope, in several hours, both will went half way (intial temp differnece is 40C, so both move 20 C, to reach final temp of 60C.
*March 21, 2015*

**science**

see the last problem. you do it this time.
*March 21, 2015*

**science**

initial temp difference is 85-40=45 C half way then is 85-45/2=62.5 C
*March 21, 2015*

**science**

Ok, sixth grader answer. You know the final temp in each will be an equal 62.5C (half way between 85 and 40). Think out why..there were equal amounts of liquid, the same liquid. So each has to change by half way, or 22.5/2 = 11.2C. Now look at liquid A. It stated at 85, in ...
*March 21, 2015*

**science**

sixth grade, ok, I figured you were in college. This is a college question. give me a couple of minutes.
*March 21, 2015*

**science**

The temperature changes are exponential. The initial difference was 68-40=28 after 5 min, the difference was 25 C after infinity, the difference will be 0C so I model the temp differnece as TempDiff=28e^kt so lets solve for k at the first five min mark 25=28e^5k or ln (25/28)=...
*March 21, 2015*

**science**

I think you are guessing. if they are exactly the same, the amount of heat one loses changes the temp the same amount as the one gaining.
*March 21, 2015*

**English**

You can do citations any way your heart desires...I go with the old Chicago style book I learned at the University of Texas in 1960. However, styles change. So use whatever your heart desires. Now if your teacher told you to use MLA, or APA, or else, you need to use those for ...
*March 21, 2015*

**science**

a. Adding OH increase the products, so the reaaction will try to undo that and move to the left. b. adding H+ increases the prducts, so the reacation will try to undo that adn move to the left. c. shifts to the right to undo the adding of the OH d. shifts to left to reduce the...
*March 20, 2015*

**physics**

1/di+1/do=1/f 1/di+1/24=1/10 24/di=2.4-1 di=1.4/24 meters=1.4/24 m then M=di/do=hi/ho solve for hi, about ho*di/do=160*1.40/24
*March 20, 2015*

**physics**

ok, vf^2=2ad acceleration=50/mass-20g*cos3.0/mass-.1*g*sin3.0 solve for vf then, KE increase=1/2 m vf^2
*March 20, 2015*

**English**

forget the intro for now. What do you want to say? Write out a outline of maybe one to three points you want to make. Now, on those points, what evidence or arguement can you make to support that point? Start writing a draft of paragraphs to support your points. Now, do you ...
*March 20, 2015*

**math**

net force=mass*acceleration mg-200v=m*a a=g-200v/mass note we have a sign issue. if g is always downward, then if v is upowrd, then a=g-200v/m but when the motion is downward, a=g+200v/m because v is now a negative sign....so on part b), one has to change the sign.. a) now we ...
*March 20, 2015*

**life orientation**

Only two? Rivalries and jealousy between cities.. wasted economic resources building stadiums.
*March 19, 2015*

**math help please**

yes
*March 19, 2015*

**Chemistry**

The 3 comes from the valence of Fe, which in this case is +3, given However, in nature, Iron reacts with dilute sulfuric acid to produce IronII sulfate and hydrogen. In Nature, iron reacts with concentrated sulfuric acid to produced IRON II Sulfate and sulfur dioxide (and ...
*March 19, 2015*

**Math Help**

You dont get it ... I think you meant this: 3/(x^2+x-2)=-1/x+2+1/x-1 factor the left side: 3/((x+2)(x-1))=A/(x+2) + B/(x-1) Now to solve A and B 3/((x+2)(x-1))=(A(x-1)+B(X+2))/((x+2)(x-1)) now comparing numerators, 3=Ax-A+Bx+2 and from that, Ax+Bx=0, or A=-B and -A+2=3 or A=-1...
*March 19, 2015*

**Math Help**

Your non use of parenthesis makes this problem undecipherable.
*March 19, 2015*

**Math**

You have to use the tools you have learned, which I have no idea what you have studied. Your calcualtor can solve this very rapidly, using Gaussian Reduction. You can use determinants, or elimination of variables. for instance, take the last two equations. Double the last one...
*March 19, 2015*

**Life orientation**

Types of representative democracy include: Electoral democracy – type of representative democracy based on election, on electoral vote, as modern occidental or liberal democracies. Dominant-party system – democratic party system where only one political party can ...
*March 19, 2015*

**Chemistry**

a. calculate the moles of reactant/products for the givens. b. use the mole ratio in the balanced equation to calcuate the unknowns. c. reconvert to mass. Example: Number 3 3Cu + 8HNO3 --> 3Cu (NO3)2 + 2NO + 4H2O given 356 grams Cu(NO3)3, or 356/187.6 moles (which is equal ...
*March 19, 2015*

**Physics**

1/2 mv^2=1.2 k x^2 solve for v
*March 18, 2015*

**physics**

fw+T=46*9.8 vertical forces. summing now about the wall.. 46(9.8)*1=T*2 tension=23*9.8 fw= First equation=you do it.
*March 18, 2015*

**physics**

time=d/5.04 time=(d+17.5)/7.26 set them equal, solve for d
*March 18, 2015*

**Math**

neither how much is five plus eight?
*March 18, 2015*

**chemistry**

Ionic? Zn + Fe+2 + SO4-2>ZnSO4 + Fe(e)
*March 17, 2015*

**Vectors**

add the two equations >>>z=-10 that allows only a) to be the answer.
*March 17, 2015*

**Algebra Help please**

that is not the answer, you need to find a, b, c.
*March 17, 2015*

**Chemistry**

No idea where to start? Read about bauxite in wiki. bauxite + sodium hydroxide>aluminum hydroxide+ heat aluminum oxide + heat + electric current> aluminum http://en.wikipedia.org/wiki/Bauxite#Processing
*March 17, 2015*

**physics**

without the picture, I have no idea.
*March 17, 2015*

**chemistry**

balance the equation: 3H2+N2>>2NH3 so you get 2/3 of the moles of Hydrogen gas.. moles H2=PV/RT
*March 17, 2015*

**Algebra**

Nope, nope.
*March 16, 2015*

**Algebra**

sinx=4/5
*March 15, 2015*

**math**

one line: y=mx+b second line perpendicular y= -x/m + c of course, you have to know m, b, c.
*March 15, 2015*

**Physic**

a. F=k/r^2 f'=-2k/r df/dr=-2k/r at r=20k -3=-k/20000 k=60,000 N so when r=10,000 df/dr=-60,000N/10,000m=-6N/m CosTheta=x/5 -sinTheta*dTheta/dt=dx/dt *1/5 but sinTheta= sqrt(5^2-x^2)/25 sinTheta=sqrt(1-(x/5)^2) solve4 for dThteta/dt
*March 15, 2015*

**precal**

Is there a question here? My crystal ball is on the blink.
*March 15, 2015*

**Physics**

energy lost in friction: mg*cosTheta*mu*distanceupplane KE lost going up the plane: mg*SinTheta*distanceupplane add those, set them equal to initial KE.
*March 12, 2015*

**math**

angle of hour hand: each 12 hours, it goes 360 deg Angle hour hand= 360*(6 48/60)/12 Angle minute hand: each hour it goes 360 det Angle Minute Hand: 360*(48/60) now subtract one angle from the other, that is the difference in angles.
*March 12, 2015*

**Physics**

tension=mg*cosTheta+v^2/r You know cosTheta, it is (1.52-.775)/1.52 solve for v at that point. Now figure total energy of the block bullet...you know KE+ PE totalENergy=1/2 m v^2+ m g h that energy is the same energy of the block when it absorved the bullet... solve for ...
*March 12, 2015*

**Chemistry help please**

pressure is directly proportional to temp in Kelvins. So change temps to K emperature(K) pressure(mm of hg) 283 726 293 750 313 800 263 880 393 960 423 ??? Now do a proportion PPP/423=960/393 check all my temp conversions, solve for PPP
*March 12, 2015*

**chemistry**

K= [B]^2*[C}/[A]^2 A=(.6-x)/4 B= (x) C=(x/2)=.2 use C to solve for x, then solve for the rest.
*March 12, 2015*

**chemistry**

ratio? O/NO=1/2 No/NO2=2/2=1/1
*March 12, 2015*

**Physics**

gravity force down the plane=mg*cosTheta friction force=mu(mg*sinTheta+F) set them equal, solve for F
*March 10, 2015*

**Science (Chemistry)**

two errors. 4*4*4 is NOT 36 the answer should be only to two sig figures.
*March 9, 2015*

**Science**

mass=density*volume=2.7*4.0^3 to two significant figures.
*March 9, 2015*

**Physics**

PV=nRT n=PV/RT use for R, units atm*liters/Kelvins change C to Kelvins
*March 9, 2015*

**MATH!!! NEED HELP FAST!!!**

C, of course
*March 9, 2015*

**chemistry**

You need to read your solubility chart. http://www.kentchemistry.com/images/links/Kinetics/Solubi1.gif what is the difference between the 80C and 10 C solubility?
*March 9, 2015*

**physics**

force*distancepushed=force*5 force=200*9.8*5/(5/sin25)=200*9.8*sin25 N
*March 9, 2015*

**math**

http://mathbits.com/MathBits/TISection/Statistics1/MAD.html mean: 3 difference: 1,1,2 mean difference=4/3
*March 9, 2015*

**math**

and the question is?
*March 9, 2015*

**physics**

Huh? This makes no sense.
*March 9, 2015*

**physics**

figure the time for each. Let d be half the distance. time1=d/80 time2=d/60 avgvelocity=2d/(time1+time2) so figure that out, I recommend do the math on time1+time2 first, solve the fraction issue...
*March 9, 2015*

**physic ap**

Nope, you are wrong. Vf=vo+g*t I have no idea how you got your answer.
*March 9, 2015*

**chemistry**

As written? As written, is says the heat of reaction is 3330J per .320g Na. lets do a proportion. 2molesNa/.320g=Hr/3330J change 2 moles Na to grms, solve for Heat of Reaction.
*March 9, 2015*

**Physics**

whatever the plane speed is, is your speed. If you walk in the plene, that walking is relative to the plane. When you jump up, and the plane is moving, the place you land is farther ahead, however, the plane has moved also, so in the plane, you land at the same spot.
*March 8, 2015*

**Physics**

acceleration=(wf-wi)/time = 2PI(.485-1.65)/12.2 displacement (radian)=avgspeed*time = 2PI(wf+wi)/2 * 12.2
*March 6, 2015*

**social studies. NEED HELP ASAP**

http://www.theweek.co.uk/middle-east/60339/eleven-things-women-in-saudi-arabia-cant-do They can vote this year in local elections.
*March 6, 2015*

**Phsyics HELP!**

The average velocity was30m/s time=distance/avbvelocity
*March 5, 2015*

**Physics**

vf^2=vi^1+2ad solve for d. Is it within the 250m runway?
*March 5, 2015*

**physics**

speed=distance/time=7.5m/s at the end, vertical veloicty=7.5 cos45
*March 5, 2015*

**physics**

angle=arc tan (2/6) IMA=3 normal force=mg=200*9.8 Newtons theoretical force=1/3 * 200*9.8 N
*March 5, 2015*

**physics**

h(t)=ho+vi*t-1/2 g t^2 ho=0 h(t)=10.1, time=1.6 solve for Vi distance to peak 1/2 mv^2=mgh solve for h
*March 5, 2015*

**math**

25 square feet.
*March 4, 2015*

**Contemporary Child Day Care**

romoting child development through parental training, among other factors, promotes excellent rates of child development-.[3] Parents play a large role in a child's life, socialization, and development. Having multiple parents can add stability to the child's life and ...
*March 4, 2015*

**Algebra**

Looks ok to me, that is the average hourly rate. Peraps the teacher is looking for the daily average rate of pay. first day=15/3=5 dollars/hr second day=45/8=5.5.63/hr avg daily rate: add them, divide by two.
*March 4, 2015*

**Algebra**

-6x = 75 x = - 75/6
*March 4, 2015*

**Algebra**

I4 has no slope. Hmmmm. That is imposible. The slope can go from negative infinity to positive infinity, inclucing a slope of zero. Now if you mean zero slope, then y= any number, it will be parallel to I4. Now when y=-3 is on the line, as given, the line is y= -3. You are ...
*March 4, 2015*

**calculus**

y=a^kx y'= k*a^(kx)*ln(a)
*March 4, 2015*

**math**

Try g(x)=x^2-2x+3
*March 4, 2015*

**geography**

Do we know where the middle is? We have not been able to see the edges yet. Whereever the middle is, we are accelerating away from it very rapidly.
*March 4, 2015*

**physics**

Is there a question here?
*March 4, 2015*

**math**

I am not certain what you mean by an area of 150+175t. 25*W=area solve for W.
*March 3, 2015*

**math**

And the question is?
*March 3, 2015*

**Chemistry**

Correct
*March 3, 2015*

**Math**

substution: y=2+2/3 x 2x-3(2+2/3 x)=6 2x-6-2x=6 no solution. graphing y=2+2/3 x one line y=2/3 x-6 second line. graph them, the lines are parallel, no solution
*March 3, 2015*

**math**

How many pieces? 3/4 is the same as 6/8 so there must be 6 pieces that are one eighth foot long, at least here in Texas.
*March 3, 2015*

**Statistics**

let me quote from a readable text: <<State the hypotheses. We begin by stating the value of a population mean in a null hypothesis, which we presume is true. For the children watching TV example, we state the null hypothesis that children in the United States watch an ...
*March 3, 2015*

**islamic studies**

Isn't this a matter of opinion? I see on cable TV lots of folks each night who seem to know the mind of God, and how to become pure of heart.
*March 3, 2015*

**physics**

what is 820 (25.9/9.8)?
*March 3, 2015*

**Calculus, HELP!!!!!!!!!**

Ok, I am lost without a picture.
*March 3, 2015*

**Physics**

first, you are adding to the normal force pushing downward. normal force=45SinTheta+mg
*March 3, 2015*

**Chemistry**

moles acid=moles base M*35ml=1.5*45ml M=? Your work makes no sense. You are supposed to be finding Molarity sodium ions
*March 3, 2015*

**physics**

Vf^2=Vi^2 +2ad so the question is, what is Vi? consider vf=vi+at Now you have two equations, two unknowns, Vf, and Vi. I would solve for Vi in the second equation, then put that in the first equation and solve for Vf
*March 3, 2015*

**algebra**

this is -+ one stad deviantion. 68 percent sare within one standard deviation.
*March 1, 2015*

**physics**

a= changevelocty/time=2(15/3.25)/3.25
*March 1, 2015*

**Physics**

at the top? g=v^2/r v=sqrt(gr)
*March 1, 2015*

**Physics**

I dont see how you handled the heat of vaporization. Sum of heats gained=0 11.4(-Hv)+681cwater*(Tf-25)+781cAl*(tf-100)=0 -11.4*540+681*1*(Tf-25)+781*.22*(Tf-100)=0 do the algebra, solve for Tf.
*March 1, 2015*

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