Friday

September 19, 2014

September 19, 2014

Total # Posts: 18,540

**science**

The magnetic monopole is a much sought after object :)
*July 12, 2014*

**science**

http://cosmoquest.org/forum/showthread.php?91956-The-Moon-Specular-and-Diffuse-Reflection
*July 12, 2014*

**science**

It is called reverberation. See: http://www.wisegeek.com/what-is-a-reverberation.htm#didyouknowout
*July 12, 2014*

**Math**

You are welcome.
*July 12, 2014*

**Math**

to fit in the box the radius of a round pizza must be less than or equal to 6 inches A = 3.14159 * r^2 = 3.14159 * 36
*July 12, 2014*

**PHYSICS**

F * 100 / 80 = 200
*July 12, 2014*

**chemistry step by step for me clearly**

sorry 3 * 6 = 18 mols
*July 12, 2014*

**chemistry step by step for me clearly**

I have to assume you mean 2.684 grams of Al2(SO4)3 and water per cc. One of those grams is water so we have 1.684 grams of Al2(SO4)3 in every cc Al2(s04)3 How many grams per mol? 2 Al = 2 * 27 = 54 3 S = 3 * 32 = 12 O = 12 * 16 = 192 so Al2 (SO3)4 = 278 grams/mol If we have 1....
*July 12, 2014*

**Physics**

How fast can the stack accelerate without the books above the first one slipping? weight down on bottom book = 5 * 4 kg * g maximum static friction force between top 5 and bottom book = 5 * 4 * g * 0.3 so max force = mass of top 5 * a 5*4*g*.3 = 5*4 * a so a = .3 g that gives ...
*July 11, 2014*

**electric circuit**

Interesting, went nameless :)
*July 11, 2014*

**Trigonometry**

A(of L and w) = L * w if w = 1 then A(L) = L
*July 10, 2014*

**stats**

57.21% or .5721
*July 10, 2014*

**stats**

I think the same as the probability that one is more than 2.90 mean = 3 we are at .1 below mean Z = -.1/.55 = -.18 from normal table if Z = -.18 then F(z) about .421 so about 42% are below so about 58 % are above 2.9 For accurate table use http://davidmlane.com/hyperstat/...
*July 10, 2014*

**error**

arithmetic! (10*9*8)/(16*15*14) = .2143 1 - .2143 = .7857
*July 10, 2014*

**Math**

p = probability defective = 6/16 = .375 1 - p = 10/16 = .625 = probability good we do three trials on the box. They all must be good if it is to pass probability of first trial fuse good = 10/16 probability of second choice being good fuse = 9/15 third = 8/14 so probability of...
*July 10, 2014*

**No picture**

If you tried to copy and paste, that does not work here.
*July 10, 2014*

**US Government**

However in real life they seem to be closer to: http://www.constitutionparty.com/our-principles/key-issues/
*July 10, 2014*

**US Government**

http://www.modernwhig.org/handbook/who-are-modern-whigs/what-we-believe I suspect Republicans like to think they share these principles.
*July 10, 2014*

**PHI 208 Week 4 Reading Quiz**

Hard to tell.
*July 10, 2014*

**Physics**

F = q E = m a so a = (q/m)E = (1.6*10^-19/1.67*10^-27)5*10^2 = 4.79 * 10^10 m/s^2 v = a t 3.5*10^4 = 4.79 * 10^10 t t = .731 * 10^-6 = 7.31*10^-7 seconds d = (1/2) a t^2 Ke = (1/2) m v^2 I think you can do c and d
*July 10, 2014*

**US Government**

http://www.fec.gov/ans/answers_pac.shtml
*July 10, 2014*

**physics**

There is indeed a magnetic dipole which has field lines of the same shape as an electric charge dipole. We also use the dipole model in fluid physics combining a source and a sink close together which also has the same sort of streamlines. All are examples of moments, meaning ...
*July 10, 2014*

**math**

Here is a picture of a similar (no pun intended) problem http://mathforum.org/sanders/connectinggeometry/ch_09Similar.html
*July 10, 2014*

**math**

No hypotenuse is necessary. We are looking at corresponding sides of similar triangles here 3/4 = h/20 so 4 h = 4 * 5 *3 h = 15
*July 10, 2014*

**Statistics/Probability**

http://davidmlane.com/hyperstat/z_table.html
*July 10, 2014*

**algebra2**

You are making as mountain out of a mole hill: 2x + 4 = 3x - 12
*July 10, 2014*

**Physics- help please**

q is the electron charge -1.6*10^-19 Coulombs You are supposed to know that, The charge on a proton is equal and opposite in sign.
*July 10, 2014*

**Physics**

v (t+2) = (1/2) a t^2
*July 10, 2014*

**math**

y = (3/5) x + b -4 = (3/5)(2) + b b = -20/5 - 6/5 = -26/5 y = (3/5) x - 26/5 5 y = 3 x - 26
*July 10, 2014*

**math**

m = (-5 - 1)/(2-4) = 3 m' = -1/m = -1/3 y = -x/3 + b find point on original line halfway between x = (4 +2 )/2 = 3 y = (1 - 5)/2 = -2 so -2 = -3/3 + b b = -1 so y = -x/3 - 1 3 y = -x - 3
*July 10, 2014*

**business**

8%/4 = 2% per quarter so every three months multiply by 1.02 25 * 1.02^n = 45 1.02^n = 1.8 n log 1.02 = log 1.8 n = 29.68 quarters or 7.42 years
*July 9, 2014*

**Urgent Calculus Help 2**

You are welcome.
*July 9, 2014*

**Urgent Calculus Help 2**

dy/dx = 6x d/dx [ln(x+4)]+ 6 ln(x+4) = 6 x /(x+4) + 6 ln(x+4) so at x = 2 dy/dx = slope = m = 12/ln(6) + 6 ln (6) but ln (6) = 1.79 so use that to find the slope m then we have y = m x + b and we know m find y at x = 2 y= 12 (1.79) = 21.5 so use that 21.5 = 2 m + b we know m, ...
*July 9, 2014*

**Urgent Calculus Help**

h' = df/dg * dg/dx at x = 2 dg/dx = -2 and g = 7 df/dg at g = 7 = -8 so -8 * -2 = + 16 that is how, you do the next
*July 9, 2014*

**ph**

For heaven's sake do what Ms Sue suggested. For me pH means acid or base. Stop wasting teacher time. We are volunteers here and you need someone who does prescriptions, not a physicist or historian. I have a sneaking suspicion you mean 250 milligrams every 8 hours for 7 ...
*July 8, 2014*

**physics**

soft spring ---> slower vibration which means longer period. You knew that. 2 pi sqrt (m/k)
*July 8, 2014*

**physics**

Northeast 65 sqrt 2 = 91.9 N
*July 8, 2014*

**Physics**

Potential energy drop = m g h =90*9.81*100 = 88,290 Joules Kinetic energy = (1/2) m v^2 = 45(900) = 40,500 Joules so loss to heat = difference = 47,790 Joules
*July 8, 2014*

**Science**

It means that there is 1/4 mol of oxalic acid in every liter of the stuff and the rest is water.
*July 8, 2014*

**TYPO**

g = -32 ft/s^2 it is -32/2 which is -16 and h(2) = (1/2)(-32) t^2 + 36 t + 4 h(2) = -16 (2)^2 + 36 (2) + 4 h(2) = -64 + 72 + 4 h(2) = 12 feet
*July 8, 2014*

**Algebra**

outside dimensions are 10+2w and 16+2w total area = 160 + 52 w + 4 w^2 pool area = 160 so sidewalk area = 4 w^2 + 52 w = 155 4 w^2 + 52 w -155 = 0 (2w-5)(2w+31) = 0 w = 5/2 = 2.5 ft
*July 8, 2014*

**Physics**

330 cos 15 = Vwest - 65 330 sin 15 = Vsouth so Vwest = 383.7 km/h Vsouth = 85.4 km/hr Vplane = sqrt (383.7^2+85.4*2) tan angle south of west = 85.4/383.7
*July 8, 2014*

**Algebra**

NO !!!!!! a straight line with y = m x + b with m negative so negative slope would satisfy answer A but the slope of these points is NOT constant
*July 7, 2014*

**Algebra**

try y = k/x for (2,30) 30 = k/2 k = 60 for (5,12) 12 = k/5 k = 60 sure enough x*y always = 60 (answer C)
*July 7, 2014*

**Algebra**

slope = change in y / change in x the change in y will not be constant unless you pick evenly spaced x values (the same changes in x) if change in y is constant for evenly spaced x values then the slope is constant so it is a straight line.
*July 7, 2014*

**phys**

Yes, assuming they are the same mass.
*July 7, 2014*

**phys**

V = x^3 dV = 3 x^2 dx dV/V = 3 x^2 dx/x^3 = 3 dx/x ah ha, C
*July 7, 2014*

**algebra**

well, look after a year .5*1.06 + .5*1.08 = 1.07 1 * 1.07 = 1.07 look after 5 years .5(1.06)^5 + .5(1.08)^5 = 1.403776827 1.07^5 =1.402551731 less look after 20 years .5*1.06^20 + .5*1.08^20 = 3.9340463 1.07^20 = 3.869684462 less Tasha wins because the 8% half makes the Tasha ...
*July 7, 2014*

**algebra**

I do not see the statements .5*(1.06)^n + .5(1.08)^n compared to 1 * (1.07)^n
*July 7, 2014*

**Algebra**

You are welcome.
*July 7, 2014*

**Algebra**

Well, that is a parabola. Where is the vertex? -16 t^2 + 48 t = h 16 t^2 - 48 t = -h t^2 - 3 t = -(1/16)h t^2 - 3 t + 9/4 = -(1/16)h + 9/4 (t - 3/2)^2 = -(1/16)(h - 36) ah ha, hits the vertex at the top when t = 1.5 seconds and h = 36 feet
*July 7, 2014*

**calculus**

y = -4 t^2 -t - 6 slope = dy/dt = -8 t - 1 at t = 8, slope = -65 so our tangent line is of form y = -65 t + b to find b, we need a point on the line when t = 8, y = -4(64) -8 -6 = -270 so use that point (8, -270) to find b -270 = -65(8) + b b = 250 so in the end y = -65 t + 250
*July 7, 2014*

**Math**

divide (-4/5) by two so -2/5 square that 4/25 add it b^2 -(4/5) b + 4/25 which is (b-2/5)^2
*July 7, 2014*

**English Essay Part 2**

Cynthia, I am so happy **that** you **** moved back to Athens. I spoke to your mom the other day.*** She told me **that** you were looking for a job. ** I know you *** worked as a cashier and a sales clerk **recently**. Therefore, I have a very special offer for you. **** I ...
*July 7, 2014*

**Math**

299
*July 7, 2014*

**Electro 1**

r = R1 R2 / (R1+R2) = 1.95*.05 /2 = .04875 In other words if connected in parallel, the .05 resistor carries practically all the current. V = 50 *.04875 = 2.4375 volts i through .05 = 2.4375/.05 = 48.75 amps i through 1.95 = 2.4375/1.95 = 1.25 amps
*July 7, 2014*

**Electro 1**

I assume the wires are in series with the load, leading to the + and - sides of the power source. total R = 6.5 ohms i = V/R = 119.6 / 6.5 = 18.4 amps V = i R = 18.4 * 6 = 110.4 volts across 6 ohm load V = i R = 18.4 * .25 = 4.6 volts across each of the two wires.
*July 7, 2014*

**PHYSICS**

F = m a 100,000 = m of ten * 2 m of ten = 50,000 kg so m of one = 5,000 kg F = m a = 5,000 * 2 = 10,000 Newtons
*July 7, 2014*

**Calculus**

Yes. The integral of the acceleration vector is the velocity vector. The constant of integration is determined by a known velocity, often the initial velocity. The integral of velocity is displacement. Constant of integration is determined by initial position (zero here) to ...
*July 6, 2014*

**algebra**

anything at all to the zero power is one.
*July 6, 2014*

**calc**

I assume both are in x, y and not three D or you would have shown 0 in y for the first and 0 in z for the second first vector: x = -82.2 + 0.2 s y = +43.0 + 1.7 s second vector: x = -84.4 + 2.4 t y = +45.5 - 0.9 t do they hit? -82.2 + .2 s = -84.4 + 2.4 t or 2.4 t - .2 s = 2.2...
*July 6, 2014*

**Math**

term 1 = a = 28 term 2 = a r term 3 = a r^2 term 8 = a r^7 = -7/32 28 r^7 = -7/32 r^7 = -1/(4*32) r^7 = -1/2^7 r = -1/2
*July 6, 2014*

**PHYSICS**

You did not ask any question.
*July 6, 2014*

**PHYSICS**

dx/dt = 28.2/9.4 = 3 cm/s for the whole trip dx/dt = (11-2.9)/(3.3-.6) = 3 cm/s for part of the trip so I suspect constant velocity of 3 cm/s or 0.03 m/s
*July 6, 2014*

**PHYSICS**

see below
*July 6, 2014*

**PHYSICS**

Hey, do it the same way.
*July 6, 2014*

**PHYSICS**

east components (x direction): -50 -25 sin 30 = -50 -12.5 = -62.5 north components (y direction) -30 - 25 cos 30 = -30 - 21.7 = -51.7 d = sqrt (62.5^2 + 51.7^2) tan angle west of south = 62.5/51.7
*July 6, 2014*

**Physics**

use law of cosines a = 95 b = 150 c = 190 c^2 = a^2 + b^2 - 2 a b cos C 36100 = 9025 + 22500 - 28500 cos C 28500 cos C = -4575 cos C = -.16053 C = 99.2 degrees now use law of sine to find the next one
*July 6, 2014*

**Math**

x = 1 and y = 10 -->1-.1 = .9 try others x = 2 and y =9 --> 1/2 - 1/9 see?
*July 5, 2014*

**SCIENCE**

70 = m v^2/r 70 = 70 (35)^2 /r r = 35^2 = 1225 http://www.jiskha.com/m
*July 5, 2014*

**Algebra**

do you mean (8n+8) ?????
*July 5, 2014*

**Algebra**

y - -1 (x^2 - 8 x + 16) + 2 y = -x^2 + 8 x - 16 + 2 y = -x^2 + 8 x - 14
*July 5, 2014*

**uos**

You problem does not make sense to me. If it slides down a vertical distance of .4 meters then we can calculate the kinetic energy (1/2) m v^2 = m g h (1/2)(2)v^2 = 20 (.4) = 8 Joules, not 60 joules. Moreover you asked for nothing, just stated impossible facts.
*July 5, 2014*

**Mathematics**

(2 pi r)(35/60)
*July 5, 2014*

**vocabulary**

You are welcome.
*July 5, 2014*

**vocabulary**

Do you not associate imagery with mental pictures?
*July 5, 2014*

**PHYSICS**

Well, force is rate of change of momentum or m A if the mass is constant, so what is the change of momentum? original momentum of driver = 52 *14 = 588 kg m/s final momentum of driver = 0 so change = -588 kg m/s How long did it take? average speed during crash = 14/2 = 7 m/s ...
*July 5, 2014*

**compound interest**

.06/12 = .005 = interest rate/month so multiply by 1.005 every month for 12 months 3500 * 1.005^12 = 3715.87
*July 5, 2014*

**physics**

Exactly, you figured it out. The man would have to pull farther (more parts in the tackle), like maybe eight times as far at 1/5 the weight
*July 5, 2014*

**Soil Chemistry**

http://www.amnh.org/exhibitions/permanent-exhibitions/rose-center-for-earth-and-space/david-s.-and-ruth-l.-gottesman-hall-of-planet-earth/what-causes-climate-and-climate-change/the-atmosphere/greenhouse-gases-a-troposphere-story
*July 5, 2014*

**Soil Chemistry**

most outgoing infrared is absorbed in the troposphere before reaching the stratosphere.
*July 5, 2014*

**Math**

10 (180-alpha) = 360 all the way around the outside 180 - alpha = 36 alpha = 144
*July 4, 2014*

**Calculus**

r = (5/8) x V = (1/3) pi [ (5/8) x ]^2 x V = (1/3) pi (25/64) x^3 etc
*July 4, 2014*

**Algebra**

sketch a graph !!!!
*July 3, 2014*

**physics**

I did #1 #2 potential energy lost = m g h potential energy gained = (1/2) k x^2 for 40 kg 40 * 9.81 * (1+x) = (1/2)(12,000) x^2 solve quadratic for x #3 I have no idea because you did not tell me ratio of bounces
*July 3, 2014*

**ACCOUNTING**

is the sum of your liabilities and ownership equity not your assets? so equity = assets - liabilities
*July 3, 2014*

**chemistry**

P V = n R T T = 16 + 273 V = 10 L = .01 m^3 n of O2 = 51.4/32 n of He = 32.5/4 calculate P of each then add to get total
*July 3, 2014*

**Urgent Calculus Help**

slope is always positive the slope keeps increasing so second derivative is positive
*July 3, 2014*

**Urgent Calculus Help**

Sketch a graph of this function. Then the answers will be obvious.
*July 3, 2014*

**Algebra**

x + (x-6) = 50 2 x - 6 = 50 2 x = 56 x = 28
*July 3, 2014*

**Physics**

m g h is the same small m needs big h Sumo seems to be 20 times as massive as the ball :
*July 3, 2014*

**Physics -- check answers please**

1. ok m g h = 20 * 10 * 2 Joules 2. No. That 400 Joules of potential energy becomes 400 Joules of kinetic energy during the fall. 3. Yes - At maximum stretch the ball stops. The ball is now 2 meters plus x below the starting point where x is the stretch distance down. The ...
*July 3, 2014*

**Social Studies**

NY heeft geen Nederlanders? Ik geloof het niet :)
*July 3, 2014*

**American national government**

separate educational facilities were inherently unequal
*July 3, 2014*

**Physics**

no constant the force increases as the spring stretches F = k x work = k x^2/2 ======================== momentum increases an external force, mg
*July 3, 2014*

**Science**

rot fungus http://en.wikipedia.org/wiki/Wood-decay_fungus
*July 3, 2014*

**Calculus 1**

A = 4 pi r^2 r = D/2 so A = 4 pi D^2/4 = pi D^2 dA/dD = 2 pi D dA/dt = 2 pi dD/dt 1 = 2 pi dD/dt dD/dt = 1/(2pi)
*July 3, 2014*

**arithmetic**

Never buy fish from a farm. Farmed fish is yuucky. Good fish comes from the ocean. lets start with 40 fish the first week 5 die so we have 35 which is 7/8 of original after first week 7/8 or 35 remain then in weeks two and three 3/5* 35 = 21 die so we are left with 35 -21 = 14...
*July 3, 2014*

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