Sunday

March 1, 2015

March 1, 2015

Total # Posts: 20,651

**physics**

angular momentum I omega does not change. If I decreases, omega increases to keep the product constant (the spinning skater pulling her arms in problem :)
*November 11, 2014*

**Math**

distance = rate * time = r t = 17 * 4
*November 11, 2014*

**English**

He wants (singular) They WANT (plural) Police is they, not he.
*November 11, 2014*

**chemistry**

that is the opposite of cloning
*November 11, 2014*

**chemistry**

I said that MIXING male and female genes ...... hastens evolution
*November 11, 2014*

**chemistry**

I can see how it might be nice to have genetically identical subjects in a lab experiment, but not in the real world. If the prototype happened to be allergic to some chemical that became common a hundred years from now, that would be unfortunate!
*November 11, 2014*

**chemistry**

It says that cloning does not allow adaptation. We need to adapt. That is what evolution is about. There is no mixing of genes in cloning. Each generation is identical to the prototype. That is a very rigid way to propagate a species, even if the prototype is Superman :)
*November 11, 2014*

**chemistry**

The problem with cloning is that mixing characteristics of male and female in the next generation increases diversity of the gene pool and hastens evolution of species to survive a changing environment.
*November 11, 2014*

**Is this right**

as far as I know
*November 11, 2014*

**Is this right**

sin (cos - sin) + cos (sin + cos) -sin^2+cos^2 + 2 sin cos I have cos^2 You have cos
*November 11, 2014*

**math**

8*6 = 48 slices total 48/24 = 2 slices each person 2/6 = 1/3 of a pie each to check 24 people * 1/3 pies/person = 8 pies sure enough :)
*November 11, 2014*

**Financing and Budget**

Yes, C
*November 11, 2014*

**Chemistry**

hard to argue with any of those
*November 11, 2014*

**Algebra Help URGENT Please?**

380/.2 = 3800/2 = 1900
*November 11, 2014*

**Algebra Help URGENT Please?**

95 + .2 s = 475 .2 s = 380 s = 380/.2
*November 11, 2014*

**Math**

yes side , side , side
*November 11, 2014*

**World History Answer Check**

That is more complete. Of course it does not cover the average dead French citizen.
*November 11, 2014*

**Algebra help URGENT Please?**

Oh, sorry, thought there were five eaters, there are 6 25/6 = about 4
*November 11, 2014*

**Algebra help URGENT Please?**

.1*124 =12.4 so.2*124 is about 25 25/5 = $5
*November 11, 2014*

**math**

what does the comma mean in F(x, y) = y cos x − xy sin x, xy + x cos x ? are we to integrate F around the perimeter of the triangle by integrating the divergence over the area or what ? Look at earlier questions below.
*November 11, 2014*

**Math**

the three sides of triangle 1 are the same length as the tree sides of triangle 2
*November 11, 2014*

**Math**

side EF = sqrt (4+4) = sqrt (8) side FD = sqrt (1+4) = sqrt 5
*November 11, 2014*

**Math**

hey if all three sides are the same it is congruent by side,side,
*November 11, 2014*

**Math**

side AB = sqrt (16+1) = sqrt 17 side BC = sqrt (4+4) = sqrt 8 side CA = sqrt (1+4) = sqrt 5 side DE = sqrt (16+1) = sqrt 17 LOL I guess you get the SSS idea
*November 11, 2014*

**Calculus**

Look at that link. It gives you the series expansion about zero explicitly.
*November 11, 2014*

**physics**

the charge on a proton is equal in magnitude and opposite in sign to the charge on a electron. Therefore if an atom has the same number of electrons as it has protons, it is neutral. Otherwise it is called an "ion".
*November 11, 2014*

**Physics**

c) (1/2) m v^2 = answer to b d) The reason they want is that the person would have reached terminal velocity where air drag up = weight down before falling 5000 meters. The reason they forgot about is that the diver also has the constant horizontal velocity of the airplane the...
*November 11, 2014*

**Did I get this right?**

yes, correct but perhaps you better multiply out and collect like terms for example 3x^2 + x^2 = 4 x^2
*November 11, 2014*

**physics**

weight = .010*9.8 = .098 Newtons x = .05 m k = 1.96 N/m omega = sqrt (k/m) = 2 pi f so f = 2.23 T = 1/f = .45 seconds
*November 11, 2014*

**Derivatives**

for starters x^3[ 4(5x-1)^3 (5) ] + 3 x^2 (5x-1)^4
*November 11, 2014*

**Square Roots**

11^2 = 121 12^2 = 144
*November 11, 2014*

**math**

yes, that makes sense. Did she get 26 ( 50/2 + 2/2 = 25+1 = 26 or did she come up with something else entirely?
*November 11, 2014*

**World History Answer Check (Ms. Sue)**

I like your other answers.
*November 11, 2014*

**World History Answer Check (Ms. Sue)**

2. What was the effect of total war on ordinary citizens during World War I? A: Because of total war, ordinary citizens underwent rationing of goods. =================================== True in the world outside the war zone, such as in the US. However ordinary French or ...
*November 11, 2014*

**Math**

I do not know what power you are raising twelve to if you mean 2 + (12)^2 then 2 + 144 = 146
*November 11, 2014*

**physics**

I need to know how far the center of mass of a blade is from the axis. If we assume the blade is a uniform rod with cg at its center (unlikely) then the moment of inertia about its end is: I = (1/3) m L^2 so for 3 we have just I = 1 m L^2 = 159 * 3.69^2 = 2165 kg m^2
*November 11, 2014*

**Math**

200 n = 3000 2 n = 30 n = 15
*November 11, 2014*

**Physics**

u = horizontal velocity = 3.2 cos 40 forever Vi = initial up velocity component = 3.2 sin 40 v = Vi - 9.8 t h = 1.175 + Vi t - 4.9 t^2 at ground, h = 0 so 4.9 t^2 - Vi t - 1.175 = 0 solve quadratic for t, use positive solution then range = u t
*November 11, 2014*

**Statistics**

well, just using what iss given and assuming it is true probability that woman uses computer at work = .72 so probability not = 1-.72 = .28 Binomial distribution prob 5/5 yes = C(5,5) .72^5 *.28^0 = 1 * .72^5 * 1 = .72^5 = .193 (second answer) so prob that someone does not = 1...
*November 11, 2014*

**physics**

seesaw :) 1 x = 35.5(1.27*10^-10 - x) 36.5 x = 45.1 * 10^-10 x = 1.24 * 10^-10 in other words right beside the Cl atom
*November 11, 2014*

**physics**

find the well depth in meters. I doubt if it is really just 10 cm deep but if really true then 0.10 meter multiply mass in kilograms by g, about 9.8 meters/second^2 to get weight force multiply that force by the depth to get work done.
*November 11, 2014*

**question**

I believe so.
*November 10, 2014*

**Math**

d = 4 t d + t = 20 5 t = 20 t = 4 d = 16 16-4 = 12
*November 10, 2014*

**Math help please!!!!!**

24/10 = 30/x 24 x = 300 x = 12.5 I am assuming that x and 10 are along the wall and not the ground.
*November 10, 2014*

**PHYSICS**

dW = p A dr dW = p 4 pi r^2 dr integrate W = p (4/3) pi (r final^3 - r initial^3) W = p (final volume - initial volume)
*November 10, 2014*

**Trigonometry**

sin^-1 (1.2 /4.4 )
*November 9, 2014*

**Physics**

F = m a 150 lbs = 68 kg Fscale up - m g down = m a Fscale up = m g + m a = 150 pounds + 68* 10 newtons = 150 pounds + 680 Newtons 680 Newtons = 153 pounds so 150 + 153 is about 300 pounds
*November 9, 2014*

**math**

65/60 is to the right of 1 on a number line. The result is positive. +
*November 9, 2014*

**Physics**

Thanks, I just went and looked, might do that but I am pretty busy here when I am not coaching our sailing team or whatever.
*November 9, 2014*

**Physics**

I will go look though.
*November 9, 2014*

**Physics**

I am a retired professor, do this for fun.
*November 9, 2014*

**Physics**

You are welcome.
*November 9, 2014*

**Physics**

Ah, here: http://earthsky.org/earth/tides-and-the-pull-of-the-moon-and-sun ( former clammer and lobsterman here :)
*November 9, 2014*

**Physics**

maximum high and low tides occur when the earth, moon and sun are co-linear. That is at full moon and new moon. Such tides are called "spring tides" and occur about twice a month.
*November 9, 2014*

**Physics**

Yes 0 free falling weightless :)
*November 9, 2014*

**Physics**

Backup link :) http://www.jiskha.com/display.cgi?id=1282164495
*November 9, 2014*

**Physics**

Like - "weightless" :)
*November 9, 2014*

**Physics**

No !!! ZERO no force on scale - in free fall, accelerating downward at 9.81 m/s^2
*November 9, 2014*

**Physics**

Total force on person = m g = m a in free fall. No external force on person from scale
*November 9, 2014*

**physics**

ke = .5 m v^2 + .5 I w^2 I = m r^2 w = v/r so ke = .5 m v^2 + .5 m r^2 v^2/r^2 ke = m v^2 v = 2.1 * 3.8 = 8.0 m/s so ke = 5.6 *64 Joules = m g h = 5.6 g h so 64 = g h h = 64/9.8 sin 17.7 = h/distance up ramp so distance up ramp = h.sin 17.7
*November 9, 2014*

**Physics**

see this similar reply http://www.jiskha.com/display.cgi?id=1415568126
*November 9, 2014*

**Chemistry**

How do you find the amount of water that reacted 2 mol of phenylmagesium bromine?
*November 9, 2014*

**Chemistry **

If there are 25 mg of water in a typical drop of water, how many drops of water would react completely with 2 mmol of phenylmagnesium bromide? How do I set up the problem?
*November 9, 2014*

**Physics**

sum of vectors, not product Pa =3.2[ 2.3 i + 4.2 j] = 7.36 i +13.44 j Pb =2.9[ -1.8 i +2.7 j] =-5.22 i +7.83 j P = (7.36-5.22) i +(13.44+7.83) j
*November 9, 2014*

**Physics**

initially p1 = 4 i + 2 j p2 = -3i + 3 j total p = 1 i + 5 j final p must be the same final p1 = px i + py j p2 = 6 i - 3 j px + 6 = 1 px = -5 vx = -5/2 = -2.5 py -3 = 5 vy = 5/2 = 2.5 so v = -2.5 i + 2.5 j
*November 9, 2014*

**physics**

no question was asked
*November 9, 2014*

**Physics**

m g h + (1/2)m v^2 = total energy = constant h is height above hanging straight down mg(2-2 cos 30)+.5m*9 = total energy = m g (2 -cos max angle when v = 0) notice m has nothing to do with this problem, cancels = mg(2-cos45) +.5 m v^2
*November 9, 2014*

**Physics**

Ke - work done against friction = (1/2)kx^2 (1/2)mv^2 - .3 m g (.2+x) = (1/2)(800)x^2 (1/2)*2*9 -.3*2*9.8(.2+x) = 400 x^2 solve quadratic for x why are you talking about m g h ??? it fell on horizontal plane?
*November 9, 2014*

**Math**

b did both draw Venn diagram fri---both- weekend |20-b | b |29-b| 20-b + b + 29-b = 40 49 - b = 40 b = 9 11 fri , 9 both , 20 weekend
*November 9, 2014*

**Calculus**

You are welcome.
*November 9, 2014*

**Calculus**

Do you mean? y= (x^3+8)/(x+2) ???? or what you typed? If my guess is correct then (bottom dtop/dx -top d bottom/dx)/bottom^2 =[(x+2)(3x^2)-(x^3+3)(1)]/(x+2)^2 =[3x^3+6x^2-x^3-3]/(x+2)^2 = (2x^3+6x^2-3)/(x+2)^2
*November 9, 2014*

**calc**

x y = 50 2 x + y = p 100/y + y = p dp/dy = 0 for min = -100/y^2 + 1 y = 10 x = 5 p = 20 feet of fence
*November 9, 2014*

**Algebra**

if x = 6 then f(x/2) = f(3) = 4 y = 4/2 = 2 (6,2)
*November 9, 2014*

**Algebra**

if x = 3 then f(x) = 4 so y = 4 + 4 = 8
*November 9, 2014*

**Physics, please!**

I used g = -10, you do it with your g
*November 8, 2014*

**Physics, please!**

I guess he kicked it horizontally? Hi = 22 0 = Hi - (1/2)(10) t^2 4.4 = t^2 t = 2.1 seconds goes 17 meters horizontal in 2.1 seconds u = 17/2.1 = 8.1 m/s
*November 8, 2014*

**Physics**

F = mu m g work = F d = mu m g d Ke lost = (1/2) m Vo^2 Vo^2 = 2 mu g d mu = Vo^2/(2gd)
*November 8, 2014*

**Algebra 2**

4x(x-6)-x(x-2)=-24 4 x^2 - 24 x - x^2 + 2 x + 24 = 0 3 x^2 -22 x + 24 = 0 18 and 4 I bet (3x - 4)(x - 6) ??? yes x = 4/3 or 6
*November 8, 2014*

**Algebra 2**

6 x^2 - 13 x + 6 = 0 we want 6 * 2 and a 1 to get 13 or 9 and 4 (3 x - 2)( 2x - 3 ) ah, 9 and 4 x = 2/3 or 3/2
*November 8, 2014*

**Algebra**

speed up = u -c speed down = u+c d = speed * time 3 = (u-c)1.5 3 = (u+c)1 1.5 u - 1.5 c = 3 1.5 u + 1.5 c = 4.5 --------------------- add 3 u = 7.5 u = 7.5/3 3 = 7.5/3 + c c = (9-7.5)/3 = 2.5/3 = .83333333333333333333333333
*November 8, 2014*

**S.S.**

Civil Rights Act of 1964? People are still discriminating against black people, particularly in the South
*November 8, 2014*

**Algebra 2**

we know that 7*7 = 49 and 49+1 = 50 so we know what to do 7 p^2 - 50 p + 7 = 0 (7 p - 1) ( p - 7) = 0
*November 8, 2014*

**Calculus (math)**

I tried method 2 but gave up about an hour ago. I do not think there is any trick, just plug and chug.
*November 8, 2014*

**Calculus**

if you were supposed to use feet instead of meters as your other problem that I just saw, use 32 ft/s^2 for g not 9.81 m/s^2
*November 8, 2014*

**Calculus**

a = g = -9.81 m/s^2 v = -gt = -9.81 t h = Hi - (1/2) g t^2 = Hi - 4.9 t^2 b) h at t = 0 = Hi h at t = 3 = Hi-4.9 t^2 = Hi - 44.1 m/s average = (-44.1)/3 = - 14.7 m/s c) at 0 v = 0 at 3 v = -9.81*3 = -29.4 m/s at 6 v = -9.81*6 = -58.9 m/s d) well I am not about to Google Hi Hi...
*November 8, 2014*

**calculus**

I mean e^x as x --> big negative is 1/e^big positive
*November 8, 2014*

**calculus**

e^-a = 1/e^a
*November 8, 2014*

**calculus**

e^x as x --> big negative is 1/e^big negative
*November 8, 2014*

**calculus**

Thought I answered this -x/e^x e^x >> x for large x
*November 8, 2014*

**Math**

C --> y S --> 3 y J --> 3 y + 50 y + 3 y + 3 y + 50 = 7 y + 50
*November 8, 2014*

**Calculus**

Oh good grief, feet :( old text had initial speed 16 ft/s up ? I guess ? h = 32 + 16 t - 16 t^2 0 = 32 + 16 t - 16 t^2 solve quadratic t = [ -16 +/- sqrt ( 256+2048) ] /-32 t = 2 seconds v = dh/dt = 16 - 32 t = 16 - 64 = -48 ft/s
*November 8, 2014*

**Algebra 2**

4 x^2 + 2 x - 2 = 0 2 ( 2 x^2 + x - 1) = 0 (2x-1)(x+1) = 0 x = 1/2 or -1 5 x^2 + 34 x - 7 = 0 (5x-1)(x+7) = 0 etc
*November 8, 2014*

**Algebra 2**

http://www.gregthatcher.com/Mathematics/GaussJordan.aspx x= 1, y=2, z = 3
*November 8, 2014*

**Calculus**

x --> + oo of -x/e^x
*November 8, 2014*

**Physics**

sqrt (251^2 + 80^2)
*November 7, 2014*

**Physics**

How long to fall 10 meters? 10 = (1/2)(10) t^2 solve for t, time in air then 4 meters = u t solve foe u
*November 7, 2014*

**Science Help!!!!**

Yes, first it is burned in the engine to make CO2 The CO2 is used in photosynthesis to make wood and leaves and stuff, releasing the O2 for us to breathe.
*November 7, 2014*

**physics**

Problem entirely vertical assuming your straight line is horizontal Vi = 10 sin 46 v = Vi - g t delta h = Vi t - (1/2) g t^2
*November 7, 2014*

**CAL**

f'(x) or d f(x)/dx y' or dy/dx maybe?
*November 6, 2014*

**Calculus**

-4 cos^3 x^4 sin x^4 (4 x^3) = - 16 x^3 cos^3 x^4 sin x^4 how that is tan x2 whatever that is I can not imagine
*November 6, 2014*

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