# Posts by bobpursley

Total # Posts: 46,573

**math**

when t is zero, W is the initial amountof water in the pool

**Calculus (increasing/decreasing)**

look at the slope in the interval, it is negative, decreasin from -sqrt5 to sqrt5 then look at x=100, slope is negative again. and at x=-100, negative again. Look at the graph here: http://www.wolframalpha.com/input/?i=(5+%E2%88%92+x%5E2)+%2F+x

**physics?**

you need to know sound power is directly proportional to sound amplitude(intensity) squared

**Physics**

constant speed: 50>Weight*g solve for W acceleration: 50>Weight(g+a)

**Science**

all human cells have the same DNA, except for Sex cells.

**math(PLEase help me check.)**

2. What is double -3? you are correct on 3) you are wrong on 1)

**Calculus**

If you mean this: lim ((-1)^n )(n/(n+1) correct.

**Science Biology**

Nope. Vacuoles are oraganella http://www.sparknotes.com/biology/cellstructure/celldifferences/section1/

**Physics**

total forces of friction: (.2*m1*g + .1*m2*g)cosTheta work that out. gravity down the plane: force=sinTheta(m1*g+m2*g) acceleration=netforce/totalmass where net force =sinTheta(m1*g+m2*g)-.2*m1*g + .1*m2*g)cosTheta calculate acceleration

**science**

In scientific argumentation, however, explanations are generated, verified, communicated, debated, and modified. Ideally, the goal of all participants in scientific argumentation is to refine and build consensus for scientific ideas, based on evidence, to come as close as ...

**Statistics**

and if you throw out the outlier, look at what happens to mean and std deviation. http://www.calculator.net/standard-deviation-calculator.html?numberinputs=9%2C8%2C+9%2C+5%2C+8%2C+9%2C+10%2C+8%2C+10&x=60&y=25

**Statistics**

range is lowest to hightest: 5 to 24, although many would throw out 24 as an outlier (look that word up) standard deviation, best done on your calculator, but http://www.calculator.net/standard-deviation-calculator.html?numberinputs=9%2C+24%2C+8%2C+9%2C+5%2C+8%2C+9%2C+10%2C+8%...

**science**

yes, he deduced.

**Physics**

densityfluid*volume=massfrog*g change all things to kg, meter

**AP Chem**

Consider the number of OH bonds dangling off of molecule D. https://www.masterorganicchemistry.com/2010/10/01/how-intermolecular-forces-affect-boiling-points/

**math**

I can't picture the shape.

**Ho...Health**

please dont post your tests here, we are not going to do them for you. We already took the course, and did not cheat by grazing for answers.

**Math**

and here is a better one https://homepage.divms.uiowa.edu/~mbognar/applets/normal.html

**Math**

change those masses in each section to standard deviations, and ... http://onlinestatbook.com/2/calculators/normal_dist.html

**Chemistry**

It is a combustible gas.

**Physics**

find the weight of the column of Hg (density*height*area). pressure then from that pressure at base of column=density*height+1atm so, the air trapped underneight it has the same pressure. Find the moles in the column vertically n=PV/RT where v=length(area). Leave Area as a ...

**Maths**

see other post.

**PHYSICS**

That is the storge capacity for that capacitor, 5micro coulombs causes one volt on the plates. one farad=he SI unit of electrical capacitance, equal to the capacitance of a capacitor in which one coulomb of charge causes a potential difference of one volt.

**Maths**

https://www.movable-type.co.uk/scripts/latlong.html is a great circle calculator, it uses the Haversine formula in spherical trig, which is seldom used anymore (I remember it from High School). Due the radius of Earth is not a perfect sphere, professor Damon's answer is ...

**Physics**

let tl be tension in the tilted cord, th tension in the horizontal cord. Horizontal: Th=Tl*cos60 Vertical: 120g=Tl*sin60 solve for Tl in the vertical equation, then th

**physics**

Wondering which is hotter to begin, the metal or the water?

**physics**

Initial heat =1.45*c*(330-Ti) c=120J/kg final heat=initial heat+2.45e4+1.45*c*(330-Ti) solve for Ti

**Maths**

there are three jumps from-12 to 18, a distance of 30.Each jump 10. -12,-2, 8,18, 28, ....

**History**

To support the public force there is a mandatory public tax. Each person is taxed based off of how much money they make and have. Baron de Montesquieu would have liked this because everyone is taxed based on how much they earn. No one person gets taxed a lot and no one person ...

**History**

these are not the words in the Declaration of Independence. You might want to check the difference. Now to get the meaning of these words, I recommend you use google and check the definitions of the following; natural inalienable sacred rights

**Chemistry**

assume 1 liter of wine, total mass 930grams. Mass of ethanol then is .14*930 Molar concentration= molesEthanol/1liter = massethanol/molmassethanol

**PHYSICS**

woltage*q=work q is the charge on an electron: 4.35516759 × 10-19 coulombs

**Physics**

1 horsepower hp = 550.00foot pounds per second ft-lb/sec

**physics**

hf=Ho-vo*t-4.9t^2 vo= -10m/s hf=0 solve for Ho

**physics**

On this, first compute the bearing based on N. Theta=arctan(E/N). If it had been some west, or S distance, you would use a negative. Positon vector, you have the N, E vectors, and now, then k= 5.2 so you have N, E, k

**physics**

well, the x component is 19costheta, and the y component is 19sintheta. draw the axis, measure the angle counterclockwise from x. This is true for any angle, say 104. If the angle had been 104 deg x=magnitude*cos104 y=magnitude*sin104 Caution: On geographical coordinates, a ...

**math**

I will be happy to check your thinking on this,it seems straightforward to me.

**Physics**

acceleration= force/(total mass) now, knowing acceleration weight= masswoman(g+a)

**Math - binomial**

https://socratic.org/questions/how-do-you-find-the-fourth-term-of-a-b-8 as an example

**physical science**

What is 1/2 * massinKg * velocityinM/S squared?

**biotechnology**

There must be some hidden question in this, but it is hidden just to well for me. And, my crystal ball is not working today.

**science (physics)**

Gauss's Law. The total of the electric flux out of a closed surface is equal to the charge enclosed divided by the permittivity. The electric flux through an area is defined as the electric field multiplied by the area of the surface projected in a plane perpendicular to ...

**Chemistry - Chemical Equilibrium**

answer to four sig digits. Wondering what to four sig digits for 273 in temp will change. I dont see any other red flags.

**science (physics)**

a gaussian surface is any surface which enclose a charge. In this case, it is six sides. You have a neat theorem from Maxwell, that tells you the net flux is equal to the charge enclosed, divided by permitivity. Gauss's Law. The total of the electric flux out of a closed ...

**physics**

the distance around once is 2PI*(radEarth+6.16e8m) velocity then= distance/period make certain distance is in meters, and period is in seconds. b. what is v^2/r ?

**science**

yes

**math**

1. second leg=sqrt(29^2-13^2)=25.9 tripexcess=25.9+13-29= not your answer 2. A=10000*1.03^35=28136 b=10000+35*300=you do it.

**Math**

Hmmmmm. What is 5*6 + 4? ans 34 what is 34/5? ans 6.8 what is 6.8 percent? ans 680 Evalyn, you are easily led astray. Don't say yes to the first boy who asks you. Please.

**physics**

wouldn't the centripetal force to keep in orbit be greater due to the increased mass? If that force is greater, it must be traveling faster (remember v^2/r ?)

**math**

take the graph 2y+Ox=10 try to plot it. It is a horizontal line, y=5. There is not a single x value.

**biology**

neurons (nerve cells) and red blood cells also cardiac cells, brain cells, corneal cells and skeletal muscle cells are stuck in the GO phase, and very seldom divide. I am pretty sure you are right.

**physics**

exactly half way? zero, there is no net force either. Remember E is a vector, and is pointing in the direction of the mass. for halfway between, the E's add to zero. b. hmmmm, just answered.

**chem**

Both of these are very dilute solutions,assume density is the same as water. percent concentrat=masssolute/(massSolution) * 100

**personal finance**

B is possible, but not often work insurance covers home injuries. He needs to check his home owners insurance policy, sometimes that covers slip and fall, including owners. If it is going to last for over a year, SSI is a likely option.

**Math**

n-7>-45 add 7 to each side n is greater than -38 balance=1625-125w 500<=balance, so 500<=1625-125w add 125w to each side, subtract 500 from each side 125w<=1125 w<=10

**Im very confused-math**

amount=rate*time 12doz=(2doz/(23/60)hr)*time 12=(2*60/23)*time 12=(120/23)*time time= 12*23/120 hrs So your thinking is off. Do the math.

**physics**

So I assume the angle theta is above the horizontal. downward force on surface=mg+Fp*sinTheta friction force=mu( Fp*sinTheta+mg) horizontal force=Fp*cosTheta when it wont move, friction>horizontal mu *Fp*sinTheta+mg*mu>Fp*costheta Fp(mu*sinTheta-cosTheta)>=mg*mu That ...

**Chemistry**

.0508*(masswater+1.79)=1.79 solve for mass water.

**Chemistry**

q=mc*delta t. you are given all, solve for mass m.

**geometry**

here is a similar problem: https://socratic.org/questions/the-perimeter-of-square-a-is-5-times-greater-than-the-perimeter-of-square-b-how- so 36 is coming to mind here...

**Math**

I bet it will be 5/4 of 12

**Chem**

ln(pressure)=?Hvap/RT + C so you have two conditions: ln(400)= ?Hvap/(R*297)+C ln(100)=?Hvap/(R*266.7) + C Hvap=(R*297)(ln400-C) Hvap=(R*266.7)(ln100-C) two equations, two unknowns. set the two equations equal, solve for C first, then go back into either equation, and solve ...

**sience**

Males have XY, females have XX.

**more physics....**

This is the problem with video instruction, I am fairly confident it was there, but you missed it, and there was no teacher to slap you when your mind drifted, or restated it so you listened.

**more physics....**

same reference as before. You need to totally understand the difference between amplitude and intensity. Intensity is energy, the square of amplitude.

**AP physics help**

amplitude is double, so intensity is ...? http://www.schoolphysics.co.uk/age16-19/Wave%20properties/Wave%20properties/text/Intensity_and_amplitude/index.html

**History**

He believed people participating in government was very important. He paid people who served. He also encouraged to introduce democracy to other parts of Greece. But I have no idea what your answer choices are, my crystal ball is not working today.

**History**

This sounds much like a multiple choice question without answers.

**Math**

what is 10/13.5 cycle/sec

**Government**

Generally, if the petition is yours, they can do nothing. Government employees are not paid, nor authorized to advocate for, things that are on petitions. There are exceptions, but few.

**help (Reading)**

Hai: I am wondering if you know what compare and contrast means? How are they alike, and how are they different? consider.. styles point of view voice subject matter type of writing

**Physics**

well, the forces are toward the other charge. There is NO FORCE at any point unless there is a charge there. There is an E field, yes, but that is not force. If you put any charge there, there would be a force away from one of the original charges, and toward the other.

**Chemistry**

find moles of O2 first. Then, use the equation: for every five mole of O2, you need one mole of P4, so figure that out, and convert moles of P4 to grams.

**Science**

tropical storm.

**college**

simple interest. 2 1/4 years is 9 quarters. Interest: 24700*9*.034/4 =

**Health check my answer**

Nope.

**English 7th Grade.**

I had already removed both, before I told you to stop in the above post.

**English 7th Grade.**

Two were posted this morning, under your name, from your computer IP address. We know things.

**beautiful galaxy girl**

Give me a break. I just gave you an example of shifting tense, with the reason for the shift. Secondly, if you post test answers again, you are out of here. Stop that. We are here to teach, not help cheat. The prior answer needs to be read carefully, as it is an example of ...

**English 7th Grade.**

I have already answered this, today I will answer it again, and tomorrow I shall have answered it three times. Will that be sufficient? Seems to me it makes the story a bit more vivid in time order, which indicates order of events. Shall I answer it again?

**Art History**

I agree.

**Physics**

hard to believe that is in a physics course, it belongs in Information Theory, or Communications Theory. But anyway, this ought to get you started: http://www.informit.com/articles/article.aspx?p=24687&seqNum=5 Stability and security: Digital is much easier to encode and hide ...

**Chemistry**

numbermolecles=moles*avagrado number = 5.2/molmass * Avagrado number so compute the molmass of C6H12O6

**physics**

I would never be able to type the math here. So print this example out, and work thru it. It is welldone. https://www.physics.purdue.edu/webapps/index.php/course_document/.../6046

**Algebra**

saleprice=OP*(1-.30)=OP*.70 Original price OP=50.40/.70

**chem**

It looks like 3 moles of S for each two moles of Al. so the answer is... (3/2)*.208

**Geometry (trig part)**

if the length of each drawbridge is L/2 (the bridge then is L across) so, if x is the distance between the tips, then x+2((Lcos20) /2)=L or x= L-Lcos20 or L(1-cos20)

**math**

Solve? There is no equal sign.

**geometry**

wondering where Point R is.

**math**

no diagram.

**Physics**

b. You know the distance in 4 seconds. Figure the distance in 3 seconds. Subtract That is the distance in the fourth second.

**Physics**

work=force*distance a) distance in four seconds: d= 1/2 at^2=1/2 (9/18)4^2=4m work=9*4 joules b) the fourth second? figure work in from zero to three, and subtract from a) above.

**Biology A**

Two kinds of UV light – ultraviolet A (UVA) and ultraviolet B (UVB) – can be used to treat skin lymphoma

**physics**

acceleration=force/mass=28/(10+4)=2m/s^2 force10kg=ma=10*2 force4kg=ma=(10*2)=20 the4 kg is pushing against the 10kg block vf=vi+at -10=20*28/14 * t t=30/2=15sec

**chemistry**

Wouldn't it depend on the ratios of vapor pressures of each at that temp?

**off subject**

you need some experience. Drama club? or similar?

**Math**

cost=flat+numberkids*costperkid 370=flat+70*costperkid 167.5=flat+25*costperkid subtract second equation from first.. 370-167.5=45*costperkid solve for costper kid, then go back and solve for flat.

**Can I publish a book?**

https://kdp.amazon.com/en_US/help/topic/G200635650

**Math**

a/(b/c)=ac/b ((3/n)-(2/m)) mn ***************** (3m-2n)(3m+2n) (3m-2m) ************* (3m-2n)(3m+2n) 1/ (3m+2n) check my work.

**English**

I think I would start with mood, point of view, foreshadowing, and imagery