Tuesday

September 16, 2014

September 16, 2014

Total # Posts: 18,517

**math**

try volume Vnew = (x+2)(x+2)(x+2) big mess try area Anew = (x+2)(x+2) = x^2 + 4 x + 4 not this for sure try that perimeter thing how many edges? 4bottom +4top +4verticals = 12 edges 12 * 2 = 24 !!! winner
*August 14, 2014*

**maths**

suspect you mean 0.10 per 1/8 mile or 0.80 per mile c(n) = 1.80 + .8 n c(4.5) = 1.80 + .8 (4.5)
*August 14, 2014*

**maths**

I told you.
*August 14, 2014*

**maths**

surface area = area of base and top (same for both) + height*2 pi r so not the same and not twice volume = area of base * height ah ha, twice if you double height
*August 14, 2014*

**Statistics**

combinations of 15 taken six at a time 15!/ [6! (15-6)!] 15! /(9! 6!) 15*14*13*12*11*10 / (6*5*4*3*2) 7*13*11*5
*August 14, 2014*

**maths**

2.25 times volume = area of base * height height the same base 1.5*1.5 = 2.25
*August 14, 2014*

**Physics**

change in potential energy = m g h = work done = 2180 Joules/second * t
*August 14, 2014*

**Physics**

r omega^2 = 9.81 m/s^2 r = (6.9/2)*1000 = 3450 m so omega^2 = 9.81/3450 omega = .0533 radians/s (that is about 118 seconds /revolution or about 2 minutes per revolution)
*August 14, 2014*

**Physics**

force * time = change in momentum = m v
*August 14, 2014*

**physics**

x displacement = 50 cos 90 + 50 cos 245 = 0 -21.43 y displacement = 50 sin 90 + 50 sin 245 = 50 -45.3 = 4.68 displacement = sqrt (-21.4^2+ +4.68^2) = 21.9 meters x is negative and y is positive so quadrant 2 tan angle above x axis = tan^-1 y/-x = tan^-1 4.68/21.43 = 12.3 deg ...
*August 13, 2014*

**math**

25 + 12*15 = 205 .12 * 205 = 24.60 saved
*August 13, 2014*

**Algebra**

either way. (a*b)/c = (b/c)a = a b / c
*August 13, 2014*

**algebra**

Please, please, try to use standard notation Do you mean (3-s)^(1/3) = 3 ??????? if so raise both sides of the equation to the third power (3 - s)^1 = 3-s = 27 s = 3 - 27 s = -24
*August 13, 2014*

**mathematics (word problems)**

.5 x + .25 x = monitor + modem .25 x remains so .25 x = 200 + 150
*August 13, 2014*

**whoops**

(m-1/4)(.8) = 3 - 1.2
*August 13, 2014*

**math**

0.10 per 1/8 mile = 0.8 per mile miles = m (m - 1/4 ).10 = 3.00 - 1.20
*August 13, 2014*

**math**

volume of box = 4*3*2 = 24 ft^3 volume of brick = 8/12 *4/12 * 2/12 = 2/3 * 1/3 *1/6 = 1/3 * 1/3 *1/3 = 1/27 ft^3 24/ (1/27) = 648
*August 13, 2014*

**Math**

You try first.
*August 13, 2014*

**math**

17 * 10^-6 mm .0 0 0 0 1 7 move that dot 6 places right and you get 17
*August 13, 2014*

**English**

http://www.sparknotes.com/lit/flies/section12.rhtml
*August 13, 2014*

**Geometry: Area and Volume Math**

I mean volume of sphere :)
*August 13, 2014*

**Geometry: Area and Volume Math**

length in cm or meters or feet or elbows or thumbs area in cm^2 or m^2 or ft^2 or elbows^2 or thumbs^2 volume in cm^3 or m^3 or ft^3 or elbows^3 or thumbs^3 areas = multiple of two lengths volumes = multiples of three lengths of course those lengths might be the same for ...
*August 13, 2014*

**Geometry: Area and Volume Math**

length * width * height 6 * 6 * 6 = 6^3 = 216
*August 13, 2014*

**math**

sin Angle = 10/20 = .5 as we all know sin 30 degrees = .5
*August 12, 2014*

**help AGAIN**

Hopefully curiosity leads to an explanation. Hopefully sincerity leads to trustworthiness.
*August 12, 2014*

**physics**

time for phase 1 = 7/9.5 = .737 hr time for entire trip = 23/22 = 1.045 hr time for 16 km = 1.045 - .737 = .308 hr speed for 16 km = 16/.308 = 52 km/hr
*August 12, 2014*

**chemistry**

P V = n R T V = n (R T/V0 so volume is proportional to number of mos if P and T are constant we need three mols of H2 for every mol of N2 so there is exactly the right amount of each for every mol of N2 we will get 2 mol of NH3 so for every mL of N2 we will get 2 mL of NH3 so ...
*August 12, 2014*

**algebra**

ok, I will try but very confusing -5 (assume x here means times, not x) -5[1/(3x+4)]^(1/3) = -10 ??????? or [1/(3x+4)]^(1/3) = 2 1/(3x+4) = 8 8(3x+4) = 1 24 x + 32 = 1 24 x = -31 x = -31/24 or do you mean -5 [(1/3)x +4 ]^(1/3) = -10 or [(1/3)x +4 ]^(1/3) = 2 ?????? (1/3) x + 4...
*August 12, 2014*

**algebra**

You notation is very hard to follow. Do you mean [ 1/(2n+3) ]^(1/4) = 3 ??? if so 1/(2n+3) = 81 81 (2n + 3) = 1 162 n + 243 = 1 162 n = -242 n = - 1.49
*August 12, 2014*

**Math**

This question could have been written another way around. Lets see how many friends Adrienne is can spend 5 dollars on in addition to spending 75 on the rental for amount in her budget c f = (c - 75)/5 NOW f depends on c but the equation is really the same 5 f = c - 75 or 75+...
*August 12, 2014*

**Math**

c = 75 + 5 f cost c depends on number of friends f
*August 12, 2014*

**Math**

ROTFL anything to the zero power is ONE one to one hundred or whatever is ONE 3^27 * 3^-9 = 3^18
*August 12, 2014*

**math PLEASE HELP**

You are welcome :) by the way 366/7 = 52 remainder 2 days Sunday - Monday is one Monday - Tuesday is two so we land there on Tuesday
*August 12, 2014*

**math PLEASE HELP**

LOL 2012 was a leap year beginning on Sunday http://www.calendarlabs.com/online-calendar.php?y=2012 Tuesday
*August 12, 2014*

**physics**

I have no idea what the statement is but in general if you drop something with no initial speed v = sqrt (2 g h) where h is height in meters g = 9.81 m/s^2 on earth v is in meters/second If you used copy and paste, it does not work here and I can not see your problem.
*August 12, 2014*

**MATH**

.5 x for film , .5 x left .25 * .5 x = .125 x on refreshments so .5 x - .125 x = .375 left for the book so .375 x = 7.50 x = 20 dollars
*August 12, 2014*

**PLEASE HELP WITH MATH**

You are welcome.
*August 12, 2014*

**PLEASE HELP WITH MATH**

If the clock spun backwards, then 20 minutes before any hour the minute hand would point to 4 assuming that the numbers remained painted on the dial as they are now.
*August 12, 2014*

**algebra**

Do you mean (1/3) + 5/(s-4) = 2 ???? if so then multiply everything by 3(s-4) (s-4) + 15 = 6(s-4) 15 = 5 (s-4) 3 = s-4 s = 9 Yes, I agree all the way.
*August 12, 2014*

**algebra**

k + 5 = -6/k k^2 + 5 k = -6 k^2 + 5 k + 6 = 0 NOTE - we have a sign problem (k+2)(k+3) = 0 k = -2 or k = -3
*August 12, 2014*

**algebra**

suspect you mean (2x+3)/x = (x+5)/2 multiply everything by 2x 4 x + 6 = x^2 + 5x x^2 + x - 6 = 0 (x-2)(x+3) = 0 x = 2 or x=-3 note I have a problem with your transition from your line two to line three 2(2x+3)=x(x+5) 4x +6=x^+5 should be 4 x + 6 = x^2 + 5x
*August 12, 2014*

**geometry**

1 m / 2 cm 14 cm (1 m / 2 cm) = 7 m 20 (1/2) = 10 m 7 (1/2) = 3.5 m
*August 12, 2014*

**Math**

14 = 7*2 always :) (x-7)(x+2) ------------------ b(Ab+3) ----------------- suspect you mean a^3-8a^2+15a which is a (a^2-8a+15) but we know 15 = 3 * 5 and 3+5=8 :) so a (a-5)(a-3)
*August 12, 2014*

**math**

circles are all geometrically similar to each other so all lengths scale the same. Both the diameter and the circumference are lengths. (1/2) 8 = 4
*August 12, 2014*

**arithematic**

1000 = (v+c)15 = 15 v + 15 c 1000 = (v-c)30 = 30 v - 30 c ------------------------------- 2000 = 30 v + 30 c 1000 = 30 v - 30 c ------------------ subtract 1000 = 60 c etc
*August 12, 2014*

**Algebra**

5 + 4 (2)^2 = 5 + 4 (4) = 5 + 16 = 21
*August 12, 2014*

**Algebra**

(4 * 1/10)^3 = 64 * 1/1000 = .064
*August 12, 2014*

**Algebra**

2*2*5 x^5 u^7 and 2*2*7 x^3 v^2 u^4 4 x^3 u^4
*August 11, 2014*

**Analytic Geometry**

sketch it first then find the lengths of the sides for example c^2 = 2^2 + 6^2 = 40 c = 2 sqrt 10 then use law of cosines a^2 = b^2 + c^2 - 2 b c cos A
*August 11, 2014*

**Analytic Geometry**

intersections: x^2 + y^2 - 2x - 2y -2 = 0 x^2 + y^2 + 2x + 2y -2 = 0 ---------------------------subtract -4x -4y = 0 x = - y so along that line of slope -1 now where does x = -y on either circle? 2 y^2 + 2y -2y = 2 y^2 = 1 y = +/- 1 x = -/+ 1 in other words at (-1,1) and (1,-1...
*August 11, 2014*

**Analytic Geometry**

I think you mean "VERTICES" or "corners" in geometry where two straight lines meet.
*August 11, 2014*

**math**

5^3 - 2^3
*August 11, 2014*

**math**

so this time they add to 90
*August 11, 2014*

**math**

supplementary angles add to 180 93 + x = 180 or x = 180 - 93
*August 11, 2014*

**physics**

250 (1000/3600) = 69.4 m/s v = Vi + a t 0 = 69.4 -10t t = 6.94 seconds to stop d = (1/2) a t^2 = (1/2)(10)(6.94^2) = 241 meters
*August 11, 2014*

**statistics gibberish**

Please proof read does body mean boys? what is 60 kg ? who got hired for what? http://davidmlane.com/hyperstat/z_table.html
*August 11, 2014*

**Algebra**

2 v^2 + 4 v - 14 = v^2 + 2 v + 1 v^2 + 2 v - 15 = 0 (v+5)(v-3) = 0 v = 3 or -5 the next one is easy
*August 11, 2014*

**Algebra**

L = 7 + 2 w L w = 99 (7+2w)w = 99 2 w^2 + 7 w - 99 = 0 (2w -11)(w+9) = 0 w = 11/2 L = 7 + 11 = 18
*August 11, 2014*

**chemistry**

By the way molecules of He is the same as atoms of He because there is one atom per molecule. If it had been H2 or O2 there would have been twice as many mols of atoms as mols of molecules.
*August 11, 2014*

**chemistry**

3 times Avagadro's number = 3 * 6.022 * 10^23 = lots of them Hey saying you have a mol of something is the same as saying you have 6*10^23 of them. It is sort of like if you say you have a dozen everyone knows you have twelve.
*August 11, 2014*

**Calculus-Math**

dC/dt = dC/dx dx/dt = 60 dx/dt = 60 [ 3(-1.637) t^2 etc
*August 11, 2014*

**Algebra**

2*3*5* w^4 * v^8 and 2*2*2*3 * y^3 * w^6 *v^2 2*3* w^4 *v^2 or 6 w^4 v^2 is all that is common
*August 11, 2014*

**Algebra**

I just did this about one minute ago. Stop spamming.
*August 11, 2014*

**Geometry**

NO lots of things with 4 straight sides are not rectangles but squares are.
*August 11, 2014*

**Algebra**

You are welcome.
*August 11, 2014*

**Algebra**

w (9-w^2) second factor is difference of squares in general a^2-b^2 = (a-b)(a+b) so w (3-w)(3+w) or -w (w-3)(w+3)
*August 11, 2014*

**physics**

Ah, ha, there was more. initial south momentum = 900 v initial west momentum = 2000 u final south momentum = 2900(16)cos 24 final west momentum = 2900(16)sin 24 so 900 v = 46400 (.9135) and 2000 u = 46400 (.4067)
*August 11, 2014*

**algerbra**

draw a number line from way left to way right +54 - (-17) = 54+17
*August 11, 2014*

**Maths literacy**

base times height. It is the same as a rectangle with a triangle taken off one end and tacked to the other end. Draw it.
*August 11, 2014*

**Maths literacy**

of what ? circle pi r^2 square s^2 rectangle L w general integral of dy dx ?
*August 11, 2014*

**math**

1= integral f(x) dx from 0 to 1 over 1 1= .5 a x^2 + (1/3) b x^3 from 0 to 1 1= .5 a + b/3 and .6 = E(x) = integral x f(x) dx .6 = = integral a x^2 + b x^3 .6 = (1/3) a + (1/4) b solve those two equations for a and b then you can do f(x) from 0 to 1/2 etc
*August 11, 2014*

**Math**

http://davidmlane.com/hyperstat/z_table.html
*August 11, 2014*

**physical science**

Just did, scroll down one question
*August 11, 2014*

**physics**

H2O = 2 + 16 = 18 grams / mol 30/18 = 1.67 mol 1.67 * Avagadro's number 1.67 * 6.022 * 10^23 = 1.004 *10^24 molecules which is quite a few
*August 11, 2014*

**Physics**

I have done several, your turn.
*August 11, 2014*

**PHYSICS**

yes * means "times"
*August 11, 2014*

**PHYSICS**

a = (.90 -0)/2.8 weight = m g = 50 (9.81) friction force = .2 * 50 (9.81) F - .2*50(9.81) = 50 (.9)/2.8
*August 11, 2014*

**physics - so what ?**

What is the question?
*August 11, 2014*

**physics**

50 min = .833 hr t1 = 3/(1.6+v) t2 = 3/(1.6-v) .833 hr = t1 + t2
*August 10, 2014*

**physics**

see this one I just did: http://www.jiskha.com/display.cgi?id=1407726270
*August 10, 2014*

**AP Stats**

By the way the formula used for linear regression is at the bottom of that web page if you need it or are doing the regression by hand. Most scientific hand calculators have an app for linear regression.
*August 10, 2014*

**AP Stats**

I have no idea what you are talking about unless you mean use regression analysis to find a best linear fit to the data. If that is what you are trying to do, Google linear regression for example there is an online calculator here: http://www.alcula.com/calculators/statistics/...
*August 10, 2014*

**maths**

B = J + 2 G = 2 B D = 2 G ---------------- so J = B - 2 G = 2 B D = 2 G = 4 B ------------------ then J + B + G + D = 38 ( B-2 ) + B + 2 B + 4 B = 38 8 B = 40 B = 5
*August 10, 2014*

**physics**

v = Vi + a t 20 = Vi + 9.5 a d = Vi t + (1/2) a t^2 108 = (20-9.5 a) (9.5) + (1/2) a (9.5)^2 solve for a
*August 10, 2014*

**Alegbra**

I do not know present value formula, using head 125/365 = .34247 so t = 8.34247 A = p e^rt 225,500 = p e^.0855 (8.34247) ln 225,500 = ln p + .71328 ln p = 11.6128 p = $110,502.72
*August 10, 2014*

**Math**

c + a = 20 so c = 20-a 12 c + 18 a = 246 12(20-a) + 18 a = 246 240 -12 a + 18 a = 246 etc
*August 10, 2014*

**Physics**

YOU MEAN: xf = xo + vot + (1/2)a t^2 How long does it take the first chestnut to reach the ground? 11 = (1/2) g t^2 t = sqrt (22/9.81) = 1.5 seconds so how long is the second one in the air? t = 1.5 - sqrt(2*2.7/9.81) = 1.5 - .74 = .76 seconds so the second one has to go 11 ...
*August 10, 2014*

**math**

do they have to be different? If not (1 + 1 + 1 + 45)/4 = 12 if they do have to be different (1 + 2 + 3 + 42)/4 = 12
*August 10, 2014*

**math**

Nancy and Sue make 11 bags the first hour all together they make 23 bags per hour they have 149 - 11 = 138 bags to make 138/23 = 6 hours so total of 7 hours 7 * 60 = 420 minutes
*August 10, 2014*

**math typo or nonsens**

Huh, Nancy and Sue make 11 bags per hour, not 12 anyway if they working together make 24 bags/hr then 149 bags / 24 bags/hr = 6.2 hr 6.2 * 60 = 372 minutes
*August 10, 2014*

**Algebra**

(15x+1)(x+2) is correct to check using FOIL First 15 x^2 Outer 30 x Inner 1 x Last 1 * 2 = 2 so 15 x^2 + 31 x + 2 to check using distributive property of multiplication 15 x ( x+2) = 15 x^2 + 30 x +1 (x+2) = x + 2 sum = 15 x^2 + 31 x + 2
*August 10, 2014*

**Algebra**

you turned the sign around in the second line w (9-w^2) w (3-w)(3+w)
*August 10, 2014*

**physics incomplete**

the answer to what you have typed is easy if they were both moving 24 deg west of south at 16 before the collision, they can continue after. However I am sure that is not the case and you have left out some initial conditions.
*August 10, 2014*

**physics**

loss of potential energy = m g (31) = 62 * 9.81 * 31 = 18,855 Joules gain in potential energy of spring = (1/2) k x^2 =.5 * k (31-12)^2 = 180.5 k so k = 18855/180.5 = 104 N/m F = m a force down = m g = 62*9.81 = 608 Newtons force up = kx when x = 31-12 = 19 F up maximum = 104*...
*August 10, 2014*

**physics**

hit at height x ball A drops h-x ball b rises x Ball A (h-x) = h - 4.9 t^2 or x = 4.9 t^2 v = -9.81 t Ball B h = Vi t - 4.9 t^2 v = 9.81 t/2 = 4.9 t so 4.9 t = Vi - 9.81 t or Vi = 14.7 t ------------------ h = 14.7 t^2 - 4.9 t^2 = 9.8 t^2 but x = 4.9 t^2 so I get half way up, ...
*August 10, 2014*

**Algebra**

we know that 81 = 9*9 and that 9+9 = 18 so try (u+9)(u+9)
*August 9, 2014*

**Calculus-Math**

d/dx (x^2y^2 - 2 x) = 2 x y^2 - 2 d/dx (2 x y^2 - 2) = 2 y^2
*August 9, 2014*

**physics**

draw picture get angles in first triangle 180 - 52 = 128 180 -128 - 33 = 19 which is angle opposite the 300 then law of sines sin 19/300 = sin 33/second slope up so second slope = 300 (sin 33 / sin 19) = 502 meters then right triangle sin 52 = h/502 h = 395 meters four ...
*August 9, 2014*

**Calculus-Math**

6 (x^2+y^2)(2x+2ydy/dx)=100(2x-2ydy/dx) find dy/dx at (4,-2) 6(16+4)(8-4dy/dx)=100(8+4dy/dx) solve for dy/dx which is m in y = m x + b then use the given point in the given equation to find b
*August 9, 2014*

**Algebra**

y^3/y^5 = y^-2 x^6 / x^4 = x^2 so y^-2 x^2 or x^2/y^2 or (x/y)2
*August 9, 2014*

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