Sunday

September 21, 2014

September 21, 2014

Total # Posts: 18,617

**chemistry. You did not ask a question**

They both displace the same volume and mass of water so both weights are reduced by density of water * g * volume of cube
*September 2, 2014*

**Algebra1**

5 c = -30 c = -6
*September 2, 2014*

**physics**

v = (4/3) pi r^3 dv/dr = 4 pi r^2 (which is the surface area of course :) dv = 4 pi r^2 dr dv/v = 4 pi r^2 dr/(4/3)pir^3 dv/v = 3 dr/r here dr = .04 and r = .84 so 100 * 3 dr/r = 12/.84 = 14.3 %
*September 2, 2014*

**Maths**

x and (60-x) now in six years Tom = (x+6) brother = (54-x) (x+6) = 2 (54-x) x+6 = 108 -2x 3x = 102 x = 34
*September 2, 2014*

**Finance**

http://www.mortgagecalculator.org/ pmt = principal [ r/ {1 - (1+r)^-n} ] here principal = 150,000 r = interest rate / month = .08/12 =.006666666 n = 12 * 30 = 360 months I get 1100.65 per month that calculator link also says 1100.65
*September 2, 2014*

**Maths,Physics,life science,geography,**

I assume you mean Vi = 100 m/s and a = -5 m/s^2 v = Vi + a t 0 = 100 -5 t t = 20 seconds to go from 100 to 0 at -5m/s^2 d = Vi (20) - (1/2)(5)(20)^2 d = 100 (20) - 2.5(400) = 2000 - 1000 = 1000 meters to stop, runs 200 meters beyond the end of the runway into the harbor where ...
*September 2, 2014*

**Math**

You only have three sides, usual solution does not apply 2 w + L = 750 (note not 2 L) so L = 750 - 2 w A = w L = w (750-2w) -2w^2 + 750 w = A w^2 - 375 w = -A/2 w^2 - 375 w + (375/2)^2 = -A/2 + 35156 (w-375/2)^2 = -(1/2)(A -70,312) max at w = 375/2 = 188
*September 2, 2014*

**math**

length = x width = 2000/x 2x + 2 (2000/x) = 180 x + 2000/x = 90 x^2 + 2000 = 90 x x^2 - 90 x + 2000 = 0
*September 2, 2014*

**Math**

circumference of tire = pi D = 36 pi =113 inches/revolution 55 mi/h (1 h/60min)(5280ft/mi)(12 in/ft) = 58,080 inches/min 58080 inches/min (1 rev/113 in) = 514 rev/min 514 rev/min ( 2 pi radians/rev) = 3229 radians/min
*September 2, 2014*

**Math, Calculus**

what angle has a cosine = .49 ?? cos^-1 .49 = 60.66 degrees so our answers are 60.66 degrees above and below the negative y axis (180 deg) 180 - 60.66 = 119.34 degrees 180 + 60.66 = 240.66 degrees
*September 2, 2014*

**Math**

radius = 20 height of center = 25 height = 25 + 20 sin [2 pi t/4 - pi/2} I use 2 pi t/4 because that gives 0 at t = 0 and a full revolution, 2 pi, at t = 4. I put in the phase of -pi/2 so that at t = 0 we have 25 +20 sin -pi/2 = 25 - 20 = 5 meters, the starting point at t = 0...
*September 2, 2014*

**Math**

2 A = 87-63 = 24 so A = 12 degrees average = (87+63)/2 = 75 so D = 75 + 12 sin (2 pi t/24 - p) where p is the phase to give the right temp when t = 5 when t = 5 sin (2 pi 5/24 - p) = -1 or 5 pi/12 - p = -pi/2 p = 6 pi/12 + 5 pi/12 = 11 pi/12 so D = 75 + 12 sin ( pi t/12 - 11 ...
*September 2, 2014*

**Math**

sqrt (25+49) = sqrt 74
*September 2, 2014*

**Physics, Math**

Archimedes says: volume of fluid displaced * density of fluid * g = upward buoyant force = weight is neutrally buoyant mass = weight/g = volume*density 2500 * 1.225 = 3063 kg up now subtract the mass of air in the balloon 2500 * rho what is rho, the density of air inside at ...
*September 2, 2014*

**chemistry**

Block A has a greater mass in 125 cm^3 than Block B has in 145 cm^3 so Block A is more dense.
*September 1, 2014*

**Physics**

d volume/d h = base area (draw a picture :) dv/dt = dv/dh * dh/dt so dv/dt = base area * dh/dt let rho = m/v of candy d m = dv (rho) so dv = dm/rho so (1/rho) dm/dt = base area * dh/dt or dm/dt = rho * base area * dh/dt = (m/v) * L * W * dh/dt
*September 1, 2014*

**calculus**

passenger ship east = 16 t if t</= 2 then 16 t is the answer if t >2 cargo ship north = 12 (t-2) (t>2 :) d^2 = (16t)^2 + 144(t^2 -4 t + 4) d^2 = 256 t^2 + 144 t^2 -576 t + 576 d^2 = 400 t^2 -576 t + 576 d = sqrt (400 t^2 -576 t + 576) check, yes that is 32 miles at t...
*September 1, 2014*

**physics**

h = (1/2)(9.81)(tfall)^2 h = 330 (7.8-tfall) 660 (7.8-tfall) = 9.81 tfall^2 9.81 tf^2 + 660 tf - 5148 = 0 for the positive root I get 7.06 so the sound comes up for 7.8 - 7.06 = .7407 seconds .7404*330 = 244 meters
*September 1, 2014*

**Math**

LOL any percent of 100 is that percent ! 64% of 100 is 64 75% = .75 = (3/4) (3/4)(60) = 3*15 = 45
*September 1, 2014*

**Please check my answers**

Richard is renamed "member" after the verb In the second one, you is renamed "member" after the verb.
*September 1, 2014*

**Math**

4 /(1/2) multiply top and bottom by 2 8 /(2/2) or 8 ================ (1/4) /(1/3) multiply top and bottom by 3 (3/4) / (3/3) or 3/4 ========================= (15/4) / (1/3) again top and bottom by 3 45/4 = 11 1/4
*September 1, 2014*

**Math**

You are welcome. By the way, (I am curious) could you be the same person with the blue and white socks question? It is another subject (probability) entirely on another level.
*September 1, 2014*

**Math**

9*70 + 60 = 630+60 = 690 RIGHT !!! 60/70 = 6/7 = .8571428571 which is .86 to the nearest hundredth so 9.86
*September 1, 2014*

**Check please**

animals is DIRECT (gave animals, not people:) ZOOS is in a subordinate phrase as is TIME THEM is it all right :)
*September 1, 2014*

**Engineering**

for anything pointy with straight sides v = (1/3) area of base * height here 300 = (1/3)(pi r^2) h so r^2 h = 900/pi
*September 1, 2014*

**Math**

200 above -30 is 170 above zero. Draw it on a number line.
*September 1, 2014*

**Math**

You are welcome :)
*September 1, 2014*

**Math**

not quite that easy you start with 30 socks p first blue =6/30 p second blue = 5/29 so .2*5/29 product is p2 blue p first white = 24/30 p second white = 23/29 product is p 2 white so add .2*5/29 + 24*23/(29*30)
*September 1, 2014*

**Math Proof**

You are welcome.
*September 1, 2014*

**Math Proof**

The key word here is ** EVERY ** epsilon, including one vanishingly small .
*September 1, 2014*

**Math Proof**

You say that as epsilon ---> 0, |x-y|--->0
*September 1, 2014*

**Math Proof**

yes it has to be for any old epsilon, including one that is vanishingly small so that the difference between x and y is so tiny it does not exist.
*September 1, 2014*

**Math Proof**

well epsilon is anything you want it to be, but usually you make it a small number and let it approach zero. If x = 5 and y = 7 then |x-y| = epsilon now we would call epsilon = 2 BUT x is only equal to y if |x-y|< ANY epsilon bigger than zero, including e = .0000000001 so ...
*September 1, 2014*

**Math Proof**

on second thought draw x as a point on a number line, then y points epsilon to the right and to the left. Then let epsilon ---> 0
*September 1, 2014*

**Math Proof**

well, draw two points on a number line maybe a distance epsilon apart then let epsilon go to zero.
*September 1, 2014*

**Math Proof**

LOL, well I suppose one could prove it somehow. It seems to belabor the obvious though.
*September 1, 2014*

**math**

You are welcome.
*September 1, 2014*

**math**

.2 p = 700 p =3500 .8 p = 2800 That sure is an expensive pair of shoes !
*September 1, 2014*

**physics**

call one charge Q1 and call Q2 = (200*10^-6 - Q1)
*September 1, 2014*

**physics**

E is the electric field, the force on a point charge of ONE coulomb. You can do it with E for either charge, ten multiply by the charge on the other (the target) sphere. Normally though you would just use the Coulomb law form F = k Q12Q2/r^2 see: http://teacher.nsrl.rochester....
*September 1, 2014*

**MAT222**

I answered this below.
*September 1, 2014*

**MAT222**

equation 1 2 y = x - 2 equation 2 2 y = x - 2 or both are y = (1/2) x - 1 They are both the same line. ANY old x and y that fits one fits the other.
*September 1, 2014*

**Math**

The math is much easier than the mind reading.
*September 1, 2014*

**Math**

Is that 3 n not on the right or is that the student's attempt at an answer?
*September 1, 2014*

**Math**

3 n^2 = 3 n n^2 - n = 0 n(n-1) = 0 n = 0 or n = 1
*September 1, 2014*

**college algebra ???**

I guess if you knew how to use parentheses to tell us what is numerator and what is denominator and what is exponent of what you would not be asking the question so I do not know what to say.
*September 1, 2014*

**math typo**

There are an infinite number of functions that pass through that point. You must tell more, like if a line give the slope.
*September 1, 2014*

**Math**

[ 3(x+2)/{(x+3)(x-3)} ] / [ 6x(x+2)/4(x+3) ] = [ 2 /{(x-3)} ] / [ x ] = 2 /[x(x-3) ] yes, agree (4/3)(x+3)/(x^2+2x)
*September 1, 2014*

**math**

check what these lines look like 2 y = 3 x - 6 5 y = - x + 1 10 y = 15 x - 30 10 y = -2 x + 2 ---------------------subtract 0 = 17 x -32 x = 32/17 (handy number :( ) y = 48/17 -3= -3/17
*September 1, 2014*

**MA112**

I answered below but d = b(c-d)/(a-b)
*September 1, 2014*

**math**

I am sure this means something to someone. Perhaps if you post it 500 times one of us will figure it out. I failed even before I got to x>#/4
*September 1, 2014*

**MATH**

(-1)^3 = -1 * -1 * -1 = -1 -3 (-1)^2 = -3 * - 1 * -1 = -3 +4 = +4 ----------------- add -1-3+4 = 0
*September 1, 2014*

**math**

0 like I said before.
*September 1, 2014*

**MA112**

You divide both sides by (a-b), not by a - b d = b(c-d)/(a-b)
*September 1, 2014*

**math packet**

n nickles (n-6) dimes 5 n + 10 (n-6) = 105
*September 1, 2014*

**math**

C + C/3 = 152
*September 1, 2014*

**algerbra**

The slopes are the same (m=4) so the lines never intersect and there is no solution.
*September 1, 2014*

**staristics**

nobody can answer that without knowing probability that an egg is rotten. Once you discover that use binomial distribution with C(24,4) = 24!/[20!*4!] times p^4 (1-p)^16
*September 1, 2014*

**Physics**

You are welcome.
*September 1, 2014*

**Physics**

You never converted km/hr to m/s go back and do the first step I gave you Vi = 60 km/h (1 h/3600 s)(1000 m/km) and you will get initial velocity = 60/3.6
*September 1, 2014*

**Physics**

I get -6667 N
*September 1, 2014*

**Physics**

Show me your steps.
*September 1, 2014*

**Physics**

no calculate Vi, the initial velocity, as I showed you. then use Vi in the last line to get a, which is negative because we are braking. Then F = m a = 1200 a
*September 1, 2014*

**Physics**

Vi = 60 km/h (1 h/3600 s)(1000 m/km) v = Vi + a t 0 = Vi + a t t = -Vi/a d = Vi t + (1/2) a t^2 25 = Vi (-Vi/a) + (1/2)a (-Vi/a)^2 25 = -Vi^2/a + (1/2)Vi^2/a 25 a = -(1/2)Vi^2
*September 1, 2014*

**math**

p^2 + p^2 + 10 p + 25 = 625 2 p^2 + 10 p - 600 = 0 p^2 + 5 p - 300 = 0 (p+20)(p-15)= 0
*September 1, 2014*

**math**

x by (2000/x) x + 2000/x = 90 x^2 - 90 x + 2000 = 0 (x-50)(x-40) = 0 I suspect it is longer than it is wide
*September 1, 2014*

**Social Studies**

Well, of course you will need a publisher for your book when you finish answering. Perhaps you could start with who won and who lost and why.
*September 1, 2014*

**geography**

convection maybe?
*September 1, 2014*

**Physics**

slope of vector A = -6.5/5 so slope of perpendicular = 5/6.5 or C dot A = 0 5 Cx - 6.5 Cy = 0 Cy/Cx = 5/6.5 if Cx = 6.5 k then Cy = 5 k C dot B = 6.5 k (-2.5) + 5 k (7) = 15 so -16.25 k + 35 k = 15 18.75 k = 15 k = .8 so Cx = .8 * 6.5 Cy = .8 * 5
*August 30, 2014*

**History**

By the way, Maine was part of Massachusetts and Vermont was either New Hampshire or New York depending on who you asked :)
*August 29, 2014*

**science**

1-.2 = .8 1-.6 = .4 .8 * .4 * 50
*August 28, 2014*

**math**

No matter how you turn it, you two are right and person z is wrong :)
*August 28, 2014*

**History**

Making it worse is that often the same crop is grown in the same field season after season, making it super easy for the bugs.
*August 28, 2014*

**History**

Those crops tend to be produced as mono cultures, mile after mile of fields of the same crop. That makes it easy for the insects to adapt to the crop culture and multiply fast without having to look around for the stuff they like. It is sort of like you are growing hordes of ...
*August 28, 2014*

**Chem Help**

whatever you are distilling boils at a lower temp
*August 28, 2014*

**algebra**

t s^2 = (R-3) s^2 = (R-3)/t s = plus or minus sqrt [(R-3)/t ]
*August 28, 2014*

**algebra**

multiply everything by 10 2 x - 5 x = 210 -3 x = 210 x = -210/3 x = -70
*August 28, 2014*

**algebra**

5/3 and sqrt 3 :)
*August 28, 2014*

**Geography**

Alaska only in the winter :) There are a lot of glaciers in Alaska but I would not say it is mainly covered in ice all year.
*August 28, 2014*

**algebra 2**

what about 1.573 ?
*August 28, 2014*

**Math Problem (please help)**

revenue = 4.59 n cost = 4000 + 2.19 n to break even: 4.59 n = 4000 + 2.19 n profit = revenue - cost 5500 = 4.59 n - 4000 - 2.19 n
*August 28, 2014*

**sorry, forgot 10, you are right**

10/k = 4.67 * 10^4
*August 28, 2014*

**Physics ...**

number produced per second = 10 number lost per second = r = k n so dn/dt = 10 - k n max when dn/dt = 0 or when n = 10/k now find k from half life experiment dn/dt = -k n dn/n = -k dt ln n = -k t + c n = Ni e^-kt when t = 3.24 * 10^3 n/Ni = .5 ln .5 = -k (3.24*10^3) -.693 = -k...
*August 28, 2014*

**science**

work = force * distance in direction of force 2.7 = 4.5 x
*August 28, 2014*

**Physics**

100 west and 100 east
*August 28, 2014*

**Physics**

20 * 200 zero again, but you know that :)
*August 28, 2014*

**Physics**

They look right to me. Of course she is not really moving it for the half of the trip that is down so you could make an argument that she is really only moving it up 450 cm and it is moving itself down 450 cm. It is the words "release" and "drop" that cause...
*August 28, 2014*

**science**

Force = charge * electric field or F = Q E if you do F = m a you can use the mass but you can use work done = change in Ke work done = change in Ke= force * distance so Q E d = Ke 2 meters= 3.25*10^-15/(1.602^10^-19 E)
*August 28, 2014*

**math problem solving**

I am assuming you mean 35,252 = 30,000 + 5,000 + 200 + 50 + 2
*August 28, 2014*

**math problem solving**

5000 50
*August 28, 2014*

**Physical sciences**

H2SO4 + 2NaOH ---> 2 H2O + Na2SO4
*August 28, 2014*

**physics**

Unless the person takes care to place the load over the original CG. People who carry burdens on their heads have great posture :)
*August 28, 2014*

**Intro Physics Help**

east 20 then west 30 then east 40 total run = 20 + 30 + 40 use for a total east = 20 - 30 + 40 use for b
*August 28, 2014*

**Science in motion pHY 102**

if both the 30 Newtons and the 20 Newtons act in the same direction then 30 N + 20 N = 50 N
*August 28, 2014*

**Math**

I think there are twice as many pairs of corresponding angles as interior because exterior also correspond. Yes of it is a parallelogram (including a rectangle). No is sides are all different lengths or for example a trapezoid. Right right
*August 28, 2014*

**math**

(7/4) * 5 = 35/4
*August 28, 2014*

**Math**

probability that he will not hit on a given shot = 3/4 probability that he will miss 4 times in a row = (3/4)^4 = 81/256 so probability that he will hit = 1 - 81/256 = 175/256 or about .684
*August 28, 2014*

**Idk..**

voter pour moi svp means vote for me please svp is abbreviation for: s'il vous plaît "if you please" I do not know what " puex to " means
*August 28, 2014*

**Math**

Huh? The three questions are all the same. Of course they all have the same answer. 0 = 4 x - 28 x = 28/4 x = 7
*August 28, 2014*

**Math**

y = k / x^3 .5 = k / 8 k = 4 y = 4 / x^3
*August 28, 2014*

Pages: <<Prev | 1 | 2 | 3 | 4 | **5** | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | Next>>