Tuesday

July 29, 2014

July 29, 2014

Total # Posts: 17,557

**math help**

That is exactly what we got x y = y x the order is just reversed

**math help**

LOL, no need for wolfram !

**math help**

remember - -d = + d

**math help**

[ (a-b) - (c-d) ] - [ (a-b) + (c-d) ] [ a - b - c + d ] [ a - b + c - d ]

**Calculus Help Please!!!**

One of us made an arithmetic mistake. It is up to Tanya to get it right :)

**Calculus Help Please!!!**

rate of change of temp proportional to temp above room temp which is 20 to make it easy on the arithmetic define T' = real T - 20 dT'/dt = k (T') dT/T' = k dt ln T' = k t T' = C e^kt let's call t = 0 at 1:30 T = 32.5 so T' = 12.5 12.5 = C e^0 = ...

**Calculus Help Please!!!**

I am going to assume it is algebra first take t = 0 at 1:30 T = Ti - k t Ti = 32.5 so T = 32.5 - k t 30.3 = 32.5 - k (1 hour) k = 2.2 so T = 32.5 - 2.2 t 37 = 32.5 - 2.2 t t = - 2.04 call it 2 hours so by that linear model 11:30 am now I will work on the more realistic calculu...

**Calculus Help Please!!!**

Are you sure this is calculus? You want exponential decay to room temp? Or is it algebra and you want a linear function?

**math**

Yes !!! You got it. even the -1 * -1 = + 1 part

**math**

sorry about the caps, was doing tax returns with caps lock on

**math**

yOU HAVE [X - [Y-Z) ] THAT IS [ X - Y - NEGATIVE Z ] - A NEGATIVE IS POSITIVE [ X -Y PLUS Z ]

**math**

x^2-(y - z)^2 exactly the same way let a = x let b = y-z now you have a^2-b^2 = (a-b)(a+b) so [x -(y-z) ] [ x + (y-z) ] (x-y+z)(x+y-z) you were close

**math**

let x = (a-b) let y = c then you have x^2 - y^2 = (x-y)(x+y) now put in (a-b) for x and put in c for y

**physics**

the only one that lacks serious damping is the light in a vacuum.

**Chemistry URGENT**

I see nothing wrong with them.

**Chemistry URGENT**

Oh, divide by 2 C6 H10 O5 + 6 O2 ---> 6CO2 + 5 H2O

**Chemistry URGENT**

C6 H10 O5 + O2 ---> CO2 + H2O we need an even number of O atoms 2 C6 H10 O5 + x O2 ---> 12CO2 + 10 H2O now O balance 10 + 2x = 24 + 10 x = 12 2 C6 H10 O5 + 12 O2 ---> 12CO2 + 10 H2O

**MATH WORD PROBLEM**

b+c = 420 so c = 420 - b c = (3/4) b so 3 b/4 = 420 - b 3 b = 1680 - 4 b 7 b = 1680 b = 240 bears total b = sb + bb but bb = (9/7)sb so 240 = sb +(9/7) sb = (16/7)sb sb = 105 small bears bb = 240 - 105 = 136 big bears I will leave the last part for you

**Chemistry**

2 * 7.9 = 15.8 mols C 15.8 * 12 g/mol = 189.6 grams of carbon

**whoops**

we got carbon as a result of step 2 so we could put it back in to step 1 then we would only need two carbons fo each CaCO3

**Chemistry**

In the end for the carbon 3 C --> CO + C + CaCO3 so in the end we need 3 C atoms for every molecule of CaCO3 C = 12 g Ca = 40 g 3O = 3*16 = 48 g so CaCO3 = 100 g/mol so we get 7.90 mols of CaCO3 for that we need 3*7.9 = 23.7 mols of C 23.7 * 12 = 284.4 grams of Carbon

**WORD PROBLEMS UGH**

kiwi need 336 * 6/8 = 252 fruits mango needs 336*3/5 = 202 fruits strawberries 336*5 = 1680 fruits total fruits = 2134

**algebra**

186 n + 30 ???? so what is the question?

**Math please check my answer?**

You are welcome :)

**Math please check my answer?**

By the way: https://www.wolframalpha.com/input/?i=e^%28x-4%29-2+

**Math please check my answer?**

again it has a horizontal asymptote of y = -2 as x--->-oo but is defined for all real x so yes, range is all real x

**math**

There is no sure answer since there is not a constant number of leaves per inch 2/3 = .67 leaves/inch 14/15 = .933 leaves /inch so 6 * .67 = 4.02 6 *.933 = 5.6 leaves per inch so probably more than four and less than 6 try 5 also see: http://www.jiskha.com/display.cgi?id=12608...

**Math**

yes, all real numbers again

**Math**

yes, all real numbers

**Physics**

well, I used 1000 for rho before I saw the hint so you use 1060 rho g h=1000*9.81*.496 = 4.86* 10^3 Pa which is 4.86 k Pa 15.02 - 4.86 = 10.15 k Pa rho g h = 1000*9.81*1.3 = 12.75 k Pa 15.02 + 12.75 = 27.8 k Pa

**algebra**

V = pi r^2 h = pi (D^2/4) H

**Math**

None of the functions you have listed seem to have zero denominators. This function has a horizontal asymptote at y = -1 as x --->-oo but is defined for all real x

**physics**

power = work/time = (25000+800)(30)/60 = 12,900 Watts or about 13 KW

**Math**

sign error add 37 x to both sides f(x) = 37 x + 82

**Calculus**

best use radians, pi/2

**History**

I think she quoted the Preamble to the Constitution.

**physics**

m1 = 40.4 x1 = 0.00 y1 = .403 m2 = 15.2 x2 = .158 y2 = 0.00 m3 = 9.49 x3 = 0.48 y3 = -.210 m = 65.09 kg x cg = [40.4*0+15.2*.158+9.49*.48]/65.09 = 0.107 m y cg =[40.4*.403+15.2*0+9.49*-.21]/65.09 = 0.22 m

**physics**

m=M/10^30 4.19*1.75 = m*(7.78-1.75) = m * 6.03 so m = 1.22 so m = 1.22 * 10^30 kg

**Math ~ Check 1 Answer ~**

You are welcome.

**Math ~ Check 1 Answer ~**

agree

**math**

a^2 + (a+1.05)^2 = 59^2 a^2 + a^2 + 2.1 a + 1.1025 = 3481 2 a^2 + 2.1 a = 3480 a^2 + 1.05 a - 1740 = 0 https://www.wolframalpha.com/input/?i=a^2+%2B+1.05+a+-+1740 a = 41.2 b = 42.2

**physics**

initial momentum = .00626*344 = 2.15 2.15 = .00626 Vb1 + 1.205*.673 Vb1 = 214 m/s exiting first block bullet momentum entering second = .00626*214 = 1.34 1.34 = 1.584 v v = .846 m/s (a) (b)final = (1/2)(1.584)(.846^2) = .567 Joules initial = (1/2)(.00626)(344)^2 =370 ratio = ....

**physics**

77.1 v = .0593 (.263) v = .000202 m/s better look fast because that blood circles around again in the body, reversing momentum :)

**Social Studies**

The way I read it: because accepting heliocentrism implied that the Bible was inaccurate since the Bible seems to support geocentrism

**Social Studies**

Agree about discontented citizens in France. steps?

**Social Studies**

The whole paragraph is about individual rights. It is not about tyranny of the majority,

**World History**

https://www.mtholyoke.edu/courses/rschwart/hist255/kat_anna/napoleon.html

**World History**

They wrecked the democracy. Napoleon just stepped in.

**World History**

No, D

**World History**

The Jacobins were world renowned radicals who turned the French revolution into chaos resulting in the Napoleonic wars and his rise to dictatorship and empire. https://www.mtholyoke.edu/courses/rschwart/hist255/kat_anna/jacobins.html

**Algebra 1**

s + (s+4) = 26 2 s + 4 = 26 2 s = 22 s = 11 which is luckily within our allowed domain :)

**Physics**

negligible :) F = G M1 M2 / d^2 F = 6.67 * 10^-11 * 443 * 356 /11.56 F = 91,000 *10^-11 = 9.1 *10^-7 Newtons

**This is madness**

I do the same question over and over. oh well s + (s+4) = 26 2 s + 4 = 26 2 s = 22 s = 11 which is luckily in our domain

**physics**

F = 9*10^9 Q1 Q2 /.16

**math**

Math - Damon, Thursday, March 27, 2014 at 11:57am A wrong .02 * .4 = .008 B wrong .03 * .4 = .012 C wrong .05 * .2 = .01 total wrong = .03 C wrong/total wrong = .01/.03 = .33

**look below**

I just did that

**Math**

A wrong .02 * .4 = .008 B wrong .03 * .4 = .012 C wrong .05 * .2 = .01 total wrong = .03 C wrong/total wrong = .01/.03 = .33

**Math**

x + 210 = 630 x = 420

**History**

Only the second choice makes any sense at all. It worked for Peter the Great.

**same question again ?**

http://www.jiskha.com/display.cgi?id=1395933159

**statistics**

9 people probability of man first = 5/9 then prob of woman = 4/8 so 20/72 for man then woman then probability of woman first = 4/9 then prob of man = 5/8 so 20/72 again add them 40/72 = .55

**physic**

m g = weight = 2*9.81 = 19.62 N static friction max = .8*19.62 = 15.7 N kinetic friction = .65*19.62 = 12.8 N 5 N does not move it. Friction resists with 5 N by third law F - 12.8 = 2 (1.5) F = 15.8 N to get 1.5 m/s^3 acceleration, it is moving now so friction force is -12.8 a...

**Algebra 2**

[ (x-y)(x+2y) ] / [(x+2y)(x+y) ] = (x-y)/(x+y)

**Equation help**

x = [ 6 +/-sqrt(36 -28) ]/2 = 3 +/- sqrt2 = 1.59 , 4.41 number 4

**I did this about ten minutes ago**

Simplify the rational expression (x^2+xy-2y^2)/(x^2+3xy+2y^2) Algebra 2 - Damon, Thursday, March 27, 2014 at 11:04am [ (x-y)(x+2y) ] / [(x+2y)(x+y) ] = (x-y)/(x+y)

**Dimensionless parameters**

You are welcome :)

**Dimensionless parameters**

By the way if gravity had been important (waves), we would have also found the Froude number v/sqrt(gL)

**Dimensionless parameters**

d/H had better be the same for model and experiment If viscosity were important then rho vL/mu, the dimensionless Reynolds number should be the same, but the problem statement says mu is not important so we are left with d/H and the ratio of force to other parameters which we ...

**CALCULUS problem**

int x^-3 dx = -.5 x^-2 + c at x = 3 = -.5/9 at x = 1 = -.5 so A = .5 - .5/9 = .5(8/9) = 4/9 B at x = h int = -.5/h^2 right half = -.5/9 +.5/h^2 left half = -.5 h^2 +.5 so -.5 h^2 + .5 = -5/9 +.5/h^2 1/h^2 = .5 + 5/9 = 4.5/9 + 5/9 = 9.5/9 = 19/18 int 1 to 3 of pi (x^-6)dx = -pi...

**who dare to give the answer!**

I not only do not dare, I do not have the slightest idea what you are talking about.

**Math**

I am not familiar with the notation but what happens is (x , y) --->(x , -y) so I would choose C.

**makes no sense**

Please check what you typed.

**typo**

same volume both times

**maths**

p = 2000 + 100 x - 6 x^2 if x = 25 p = 2000 + 2500 - 3750 p = 750 not a wise decision unless there is a typo

**math**

Well, let's hope we are right :)

**math**

surface area = 4 pi r^2 so dv/dt = 4 pi r^2 dr/dt dv/dt = 75 cm^3/s so dr/dt = 75/(4 pi r^2) when r = 5 dr/dt = 3/(4 pi) = .75/pi cm/s after 60 seconds volume = 75*60 = 4500 cm^3 (4/3)pi r^3 = 4500 pi r^3 = 3375 r = 15/pi^(1/3) r^2 = 225/pi^(2/3) 4 pi r^2 = 900 pi^(1/3) dr/dt ...

**social study**

http://gloucester-ma.gov/index.aspx?nid=649

**social study**

here's one here: http://wgbhnews.org/post/wind-turbines-power-gloucester-city-buildings

**Calculus**

huh?

**Calculus**

x = ln 243 y = ln 32 LET Z = e^((3x + 4y)/5) ln [z ]= (3x+4y)/5 ln z = (1/5)( 3 ln 243 + 4 ln 32) = ln (243^3/5 *32^4/5) = ln (27*16) = ln(432) if ln z = ln 432 then z = 432

**physics**

v = Vi -7.1 t 0 = 43 - 7.1 t t = 43/7.1 = 6.06 s average speed during stop = 7.1 /2 =3.55 m/s d = 3.55 * 6.06 = 21.5 m

**Physics Help**

Pairs of forces probably refers to Newton's third law, for every force there is an equal and opposite force.

**Physics Help**

Impulse is mass times change in velocity because Force * time = change of momentum = change of m v = m * change of v if m is constant

**physics**

potential energy of each at start = k q^2/r at large distance that energy is kinetic so (1/2)m v^2 = k q^2/r

**Chemistry**

ml ranges from -L to +L If L = 0, ml = 0

**Chemistry**

4 is out because with L = 0 you have no choice of ml = 1. wtih L = 0 ml = 0 and spin can be 1/2 or -1/2 ml = 1 is not allowed if L = 0

**Chemistry**

3) is out, spin is =/- 1/2 1) is out, negative L 2) is out , biggest L is n-1 or 2 4) is out, with L=0 you only have +/- 1/2 for spin, no ml - 1 5) looks possible 6) looks possible

**Alegbra**

You are welcome :)

**Alegbra**

Yes, right :)

**Alegbra**

LOL -1/3 = -0.33333333333333333

**Alegbra**

It would really help you if you sketched these points on a graph, or at least the x values on a number line.

**Alegbra**

from G to H x goes from 3 to -2 or -5 easier for me to go (1/3) of 5 from H to G so -2 + 5/3 which is -6/3 + 5/3 or x = -1/3

**Alegbra**

You are welcome.

**Alegbra**

Hailey to find something halfway in between, just take the average which is the sum divided by two

**Alegbra**

If you men the earlier question I gave you both x and y of the point. Y is 1/2

**Math**

prob that next one is above 75 = .6 prob that the one after that is independently .6 again so probability of both = .6*.6 = .36

**math**

(2/5) * 50 = 20 tigers (1/5) * 50 = 10 leopards sum = 30 so 50 - 30 = 20 lions

**Math**

yes

**Math**

3.3636... > 3.3333...

**math**

x = 38 + 5 t y = 30 + 7 t when does x = y? 38 + 5 t = 30 + 7 t 2 t = 8 t = 4 hours

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