Saturday

November 22, 2014

November 22, 2014

Total # Posts: 19,402

**CALCULOUS**

1.043^n = 2 n log 1.043 = log 2 n = log 2/log 1.043 = 16.5 years
*October 3, 2014*

**Science**

http://www.jiskha.com/display.cgi?id=1412288943
*October 2, 2014*

**Very important**

Go back and read my reply about the bottles moving at constant velocity !!!!
*October 2, 2014*

**Science**

a = 2 (1.5)/3.6^2
*October 2, 2014*

**sign error**

-h/h or -1
*October 2, 2014*

**Math**

f(2+h) = |2+h-5|-7 = |h-3| -7 as h---> 0 this is 3-h-7 = -h -4 f(2) = |-3| -7 = 3-7 = -4 so [ -h - 4 + 4 ] /h = h/h = 1
*October 2, 2014*

**What collision, where?**

I do not read minds.
*October 2, 2014*

**Physics**

I just showed you how to do the one with the train and the car.
*October 2, 2014*

**Physics**

car: v = 36 + 4 t x = 35 + 36 t + 2 t^2 train v = 22 x = 22 t the time t and the position x are the same at passing 22 t = 35 + 36 t + 2 t^2 solve quadratic for t go back and find v = 36+4t
*October 2, 2014*

**physics**

F sin 30 = 1.2 sin 30 = 1/2 F = 1.2/(1/2) = 2.4 N
*October 2, 2014*

**Science**

NO No NOOOO !!!!!! constant velocity is NO FORCE very, very important Force = mass * ACCELERATION not velocity but CHANGE in velocity/time
*October 2, 2014*

**Science**

F = m a = change in momentum/change in time (again) if there is no change in velocity there is no change in momentum and the net force on the bottle is zero so the forces are "balanced".
*October 2, 2014*

**physics**

|F| = sqrt (8.85^2 + 2.21^2) m = |F|/a = |F|/4.4
*October 2, 2014*

**Science**

F = m a =change of momentum/change in time so it accelerates, changes velocity
*October 2, 2014*

**physics**

a) m g h b) (1/2) m v^2 c) answer a - answer b = energy lost to friction energy lost to friction = work done by friction (friction force on tree *distance down) so friction force = energy lost/13 meters
*October 2, 2014*

**physics**

initial potential and total energy = E =m g h there is no friction in this problem so the total mechanical energy stays the same (1/2) m v^2 + m g h = E at every height h, you can calculate v
*October 2, 2014*

**Social Studies**

I believe that you are correct. I am sure that D is incorrect :)
*October 2, 2014*

**Physics**

10 min = 600 seconds 2,000 watts * 600 seconds = 1,200,000 Joules = 1.2*10^6 = 12 * 10^5
*October 2, 2014*

**Math Help!!**

In other words I think question 8 is missing the word "not".
*October 2, 2014*

**Math Help!!**

In number 8, B is the only one that is not a repeater https://www.google.com/search?q=repeating+decimal+definition&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=sb
*October 2, 2014*

**Math Help!!**

When in danger or in doubt, sketch the problem on a number line :)
*October 2, 2014*

**Math Help!!**

3. 7.2 x 12 x 0.23 = ? Round to the nearest hundredth. 19.872 since 2 is less than five, the nearest hundredth is 7 so 19.87 which is C as Brady said.
*October 2, 2014*

**Geometry**

(4/3)pi r^3 = 3,000 r^3 = 9000/(4 pi) r = [9000/(4 pi)]^(1/3) 4 pi r^2 = 4 pi [9000/(4 pi)]^(2/3)
*October 2, 2014*

**Science--3 questions? :c**

http://en.wikipedia.org/wiki/Nebular_hypothesis longitude altitude
*October 2, 2014*

**Science**

suspect you mean evolution on which case I would vote for a) with Darwin genetic adaptation http://grapes.msu.edu/integrated_pest_management/how_pesticide_resistance_develops
*October 2, 2014*

**Int. science**

I agree :)
*October 2, 2014*

**Int. science**

Oh, please guess !
*October 2, 2014*

**statistics**

I think you mean standard deviation of 9 http://davidmlane.com/hyperstat/z_table.html
*October 2, 2014*

**Distributive Property Algebra**

8(6 - 2) = 8(6) - 8(2) by distributive property of multipication = 48 - 16 = 32 --------------------------- You could also say 8*4 = 32 but that does NOT USE distributive property. ------------------------- 7 c + 7*4 by distributive property then = 7 c + 28
*October 2, 2014*

**science**

I am assuming that you are correct; the water evaporates
*October 2, 2014*

**physics**

That depends If you are in an car: If it is taking off from a stop light and accelerating forward then Thrust is greater than Drag If it is cruising along at constant velocity then Thrust forward equals drag back If you take your foot off the gas and coast then Thrust becomes ...
*October 2, 2014*

**physics**

drag is normally opposite to velocity.
*October 2, 2014*

**Algebra**

You are welcome.
*October 2, 2014*

**Algebra**

5m and 3 m are indeed like terms (combine like terms to make 8 m + 6 p + 4)
*October 2, 2014*

**Math**

(A) 2/5 (B) 2/5 = 24/60 (C) 2/5= what/35 multiply 2/5 by 7/7 and get 14/35 so 14
*October 2, 2014*

**Intro to Physical Science**

m g h = potential energy at top = 100 * 9.81 * 12 = 11,772 Joules loses 3550 Joules so (1/2) (100) v^2 = 11,772 - 3550 = 8222 Joules v = 12.8 m/s
*October 2, 2014*

**Math**

17 * 85/6
*October 2, 2014*

**n2 maths**

pi (25)^2/4 * 40 = n (4/3) pi (3)^3 6250 = 36 n
*October 2, 2014*

**math n2**

tan 58 = h/380
*October 2, 2014*

**physics**

d = .5 a t^2 a = 6/t .01 = .5 (6/t)t^2 = 3 t t = .00333 s F = change in momentum/change in time = .45 *6/.00333 = 810 Newtons
*October 1, 2014*

**physics**

10^3*10^8 = 10^11
*October 1, 2014*

**Physics**

h = (1/2) g t^2 in metric, g = 9.81 meters/s^2 in English g = 32 feet/second^2
*October 1, 2014*

**calc / physics**

yes yes
*October 1, 2014*

**Algebra**

- x^4 always - (-x)^4 always + x either -x either
*October 1, 2014*

**Math**

f(8+h) = sqrt (8+h) - 8 f(8) = sqrt(8) - 8 subtract sqrt (8+h) -sqrt (8) but d/dh (8+h)^.5 = .5 (8+h)^-.5 so sqrt (8+h) = sqrt 8 + .5 h/sqrt(8+h) subtract sqrt 8 .5 h/sqrt(8+h) divide by h .5/sqrt (8+h) let h -->0 .5/sqrt 8
*October 1, 2014*

**math**

x = [ -5 +/- sqrt(25 + 8) ]/4 = [ -5 +/- sqrt (33) ]/4
*October 1, 2014*

**physics**

a = change in velocity / change in time -.87 = change in velocity / 3.8 so change in velocity = -3.3 m/s
*October 1, 2014*

**Chem 400**

It is there 0.6548 g/mL *10^-3 mL/ uL =.6548 *10^-3 g/uL
*October 1, 2014*

**Chem 400**

hexane is 86 g/mol we have 55 uL *.6548 *10^-3 g/uL = 36*10^-3 g 36*10^-3/86 =4.2 * 10^-4 mol * 6*10^23 = 2.51*10^20 molecules of hexane now just add up the protons in a molecule and divide. It is C6H14 C has 6 each and H has 1 each
*October 1, 2014*

**math**

-50 3/4 = -203/4 = - 5075/100 -6.05 = -605/100 100 = 10,000/100 so (-5075 -605 + 10,000)/100 = 4320 / 100 = 43.2
*October 1, 2014*

**Printing press**

Good grief !!! Google Gutenburg
*October 1, 2014*

**Math**

8 j + 4 d = 64 4 j + 8 d = 92 multiply first eqn by 2 16 j + 8 d = 128 4 j + 8 d = 92 --------------- subtract 12 j = 36 j - 3 dollars per jump rope then d = 10 dollars per doll You can do it now
*October 1, 2014*

**math**

7 a + 3 s = 1625 s = 2 a so 7 a + 3 (2 a) = 1625 7 a + 6 a = 1625 13 a = 1625 a = 125 so s = 250
*October 1, 2014*

**Chemistry**

Huh ?? a mole of anything is about 6*10^23 of them like a dozen is 12 of something 2.65*10^15 ----------- 6 * 10^23 = .442 *10^-8 = 4.42 * 10^-9 moles
*October 1, 2014*

**Math**

546*714 /(42*42) = 221 but, is that exact? 546 / 42 = 13 714 / 42 = 17 yes, tiles do not have to be cut.
*October 1, 2014*

**math**

100 + 10(150 - 50)
*October 1, 2014*

**Math help!**

c - distributive d - commutative
*October 1, 2014*

**History**

I am no scholar of the period but am having trouble imagining the Italian cities working together to do this. Do you mean Venice and Genoa cooperating ?
*October 1, 2014*

**chemistry**

Xe = 131 g/mol F = 19 g/mol so XeFn = (131 + 19 n) g/mol or (131+19n)g / 6*10^23 molecules but this stuff is .368 g/9.03*10^20 molecules .368/9.03*10^20 = (131+19n) /6*10^23 131+19 n = 244.5 g/mol 19 n = 113.5 n = 6 so XeF6
*October 1, 2014*

**History**

That is just a symptom of the importance though. There is much more but I would have to write a book for you.
*October 1, 2014*

**History**

LOL gmta
*October 1, 2014*

**History**

What language do they speak there now?
*October 1, 2014*

**Math (for Damon)**

You are welcome :)
*October 1, 2014*

**Math (for Damon)**

weight of single Steven box (English unclear) = s so weight of a Nathan box = s+12 so weight lifted by Nathan = 13(s+12) agree but sentence could mean total weight of boxes lifted by Steven = s then each steven box weighs s/15 then a nathan box weighs (s/15) + 12 and total ...
*October 1, 2014*

**English**

can play looks like a compound verb to me
*October 1, 2014*

**Math**

change in x = 3 change in y = 5 hypotenuse = sqrt (9+25) = sqrt (24) = sqrt (4*6) = 2 sqrt 6
*October 1, 2014*

**Math ????**

What do you want to know? The slope between those two point? the distance between them?
*October 1, 2014*

**physics**

v = Vi + a t =3.25 + 3.2*4.4
*October 1, 2014*

**Math plz.**

z(1-2+4) + 6 3 z + 6
*October 1, 2014*

**Math question? :c**

7*c + 7*4 = 7 c + 28
*October 1, 2014*

**math**

2588 - 188 = 2400 2400 / 24 = 100 per payment
*October 1, 2014*

**math**

.75 p = p - 180 yes I do not know what the second question is.
*October 1, 2014*

**1 math question**

8*6 = 48 8*2 = 16 so 8(6-2) = 48-16 = 32
*October 1, 2014*

**physics**

here http://en.wikipedia.org/wiki/Geostationary_orbit 35,786 kilometers above earth
*September 30, 2014*

**physics**

look up geostationary satellite
*September 30, 2014*

**physics**

F = m v^2/r
*September 30, 2014*

**Algebra**

Yes.
*September 30, 2014*

**Algebra**

(-7,3) I think I do not do interval notation either.
*September 30, 2014*

**Algebra**

(x+2) < 5 and -(x+2) <5 x < 3 and (x+2) > -5 x < 3 and x > -7 which is -7 < x < 3
*September 30, 2014*

**Physics-Intro**

good grief, I have not seen those units for a while still F = m a force and weight in pounds, mass in slugs acceleration in ft/s^2 F = 25,000 * 28 = 700,000 pounds
*September 30, 2014*

**physics**

.424 * 10^8 m/s = 4.24 * 10^7 or a bit over a tenth of the speed of light.
*September 30, 2014*

**Algebra 2 Answer Check**

2 y = -5 x + 8 y = -(5/2) x + 4 slope = -5/2 so slope of perpendicular = 2/5 y = -(2/5) x + b 3 = -(2/5)5 + b 3 = -2 + b b = 5 y = -(2/5) x + 5
*September 30, 2014*

**Algebra 1**

1 a try x = -1 1 </= -1 nope b x = -1 works but x = 10 fails totally c x^2 </= 23.25 x^2 x^2 always + so this works by the way d is 4 x^2 -24 x + 36 >/= 4 x^2 - 3 -24 x + 39 >/= 0 nope
*September 30, 2014*

**Typo**

If you are really serious about only 11 meters^2 then (w+6)w = 11 w^2 + 6 w - 11 = 0
*September 30, 2014*

**Physics**

F = m a Ft = tug force = - Fa asteroid force 3360 vt + 6300 va = 0 momentum remains 0 490 = 3360 at -490 = 6300 aa at = .146 m/s^2 aa = -0.778 m/s^2 vt = 0 + .146 t va = 0 - .778 t position t = .5 (.146)t^2 430 - position a = .5 (-.778)t^2 they are headed toward each other so ...
*September 30, 2014*

**Trigonometry**

if theta is between 0 and -90 (quadrant 4) the sin is negative. Therefore we only look at quadrant one. sin^-1 0.95 = 71.8 degrees
*September 30, 2014*

**chemistry**

first balance 2 NaClO + H2O --> 2 Na+ +2OH- + Cl2 + O2 How many mols of NaClO ? Na = 23 g/mol Cl = 35.5 O = +16 so NaClO = 74.5 g/mol 2 NaClO = 149 g then grams of NaClO = .0585 *1.12*15 = .983 grams of NaCl .983/74.5 = .0132 mols of NaClO we get half as many mols of O2 so ...
*September 30, 2014*

**Algebra**

L = w + 4 L w = 165 (w+4)w = 165 w^2 + 4 w - 165 = 0 (w+15)(w-11) = 0 w = 11
*September 30, 2014*

**Physics**

phase 1 v = 5 t , slope up of 5 up to Vi = 25 phase 2 v = constant = 25 from t = 5 to t = 20 phase 3 v = 25- 5(t-20), slope down of -5
*September 30, 2014*

**Pre-Calculus/Trigonometry**

You are welcome :)
*September 30, 2014*

**Pre-Calculus/Trigonometry**

would it be like this for a, and if so how would i continue that? (f o g)(x)= 1/[(f o g)(x)-5]? ======================= no, just do what it says f (g(x)) use g(x) = (x^2+2) for argument of f in other words f (x^2+2) = 1/[ (x^2+2) - 5 ]
*September 30, 2014*

**Pre-Calculus/Trigonometry**

replace x by x^2+2 1/[ (x^2+2) -5 ] = 1/(x^2 - 3) b. f(6) = 1/1 = 1 g(1) = 1+2 = 3
*September 30, 2014*

**precal**

9 9r 9r^2 9r^3 -72 = 9 r^3 r^3 = -72/9 now work back a9 = 9/r a8 = 9/r^2 a7 = 9/r^3 interesting a7 = 9/r^3 = (9)(-9/72) = -81/72
*September 30, 2014*

**physics**

I could swear I did this one yesterday :( ball 1 d = distance down d = .5 g (t+1)^2 ball 2 d = 40 t + .5 g t^2 so .5 g (t^2 + 2 t + 1) = 40 t + .5 g t^2 put in whatever you use for g (9.81, 9.8 or 10) and solve the quadratic
*September 30, 2014*

**ALgebra 2**

From 0 go left 1/2 then go left another 3/4 see that you are now at -1 1/4
*September 30, 2014*

**ALgebra 2**

-2/4 - 3/4 = -5/4 = -1 1/4 Sketch this on a number line !!!!
*September 30, 2014*

**mathematic**

p = r - c p = 150 n - 850 - 76 n p=74n-850
*September 30, 2014*

**math exponential function**

450 (1.06)^(2n) = 477 1.06^2n = 1.06 n = 1/2 year
*September 30, 2014*

**Calculus**

ln y = x ln 2 1/y dy/dx = ln 2 dy/dx = y ln 2 or dy/dx = 2^x ln 2
*September 28, 2014*

**physics**

time for first rock -20 = -5 t^2 t = 2 seconds to fall so t for second ball = 2 - 1 = 1 second -20 = -Vi t + -5 t^2 20 = -Vi + 5 Vi = -15 m/s (the - sign means speed is down)
*September 28, 2014*

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