Sunday

September 21, 2014

September 21, 2014

Total # Posts: 18,583

**PHYSICS**

F = m a 100,000 = m of ten * 2 m of ten = 50,000 kg so m of one = 5,000 kg F = m a = 5,000 * 2 = 10,000 Newtons
*July 7, 2014*

**Calculus**

Yes. The integral of the acceleration vector is the velocity vector. The constant of integration is determined by a known velocity, often the initial velocity. The integral of velocity is displacement. Constant of integration is determined by initial position (zero here) to ...
*July 6, 2014*

**algebra**

anything at all to the zero power is one.
*July 6, 2014*

**calc**

I assume both are in x, y and not three D or you would have shown 0 in y for the first and 0 in z for the second first vector: x = -82.2 + 0.2 s y = +43.0 + 1.7 s second vector: x = -84.4 + 2.4 t y = +45.5 - 0.9 t do they hit? -82.2 + .2 s = -84.4 + 2.4 t or 2.4 t - .2 s = 2.2...
*July 6, 2014*

**Math**

term 1 = a = 28 term 2 = a r term 3 = a r^2 term 8 = a r^7 = -7/32 28 r^7 = -7/32 r^7 = -1/(4*32) r^7 = -1/2^7 r = -1/2
*July 6, 2014*

**PHYSICS**

You did not ask any question.
*July 6, 2014*

**PHYSICS**

dx/dt = 28.2/9.4 = 3 cm/s for the whole trip dx/dt = (11-2.9)/(3.3-.6) = 3 cm/s for part of the trip so I suspect constant velocity of 3 cm/s or 0.03 m/s
*July 6, 2014*

**PHYSICS**

see below
*July 6, 2014*

**PHYSICS**

Hey, do it the same way.
*July 6, 2014*

**PHYSICS**

east components (x direction): -50 -25 sin 30 = -50 -12.5 = -62.5 north components (y direction) -30 - 25 cos 30 = -30 - 21.7 = -51.7 d = sqrt (62.5^2 + 51.7^2) tan angle west of south = 62.5/51.7
*July 6, 2014*

**Physics**

use law of cosines a = 95 b = 150 c = 190 c^2 = a^2 + b^2 - 2 a b cos C 36100 = 9025 + 22500 - 28500 cos C 28500 cos C = -4575 cos C = -.16053 C = 99.2 degrees now use law of sine to find the next one
*July 6, 2014*

**Math**

x = 1 and y = 10 -->1-.1 = .9 try others x = 2 and y =9 --> 1/2 - 1/9 see?
*July 5, 2014*

**SCIENCE**

70 = m v^2/r 70 = 70 (35)^2 /r r = 35^2 = 1225 http://www.jiskha.com/m
*July 5, 2014*

**Algebra**

do you mean (8n+8) ?????
*July 5, 2014*

**Algebra**

y - -1 (x^2 - 8 x + 16) + 2 y = -x^2 + 8 x - 16 + 2 y = -x^2 + 8 x - 14
*July 5, 2014*

**uos**

You problem does not make sense to me. If it slides down a vertical distance of .4 meters then we can calculate the kinetic energy (1/2) m v^2 = m g h (1/2)(2)v^2 = 20 (.4) = 8 Joules, not 60 joules. Moreover you asked for nothing, just stated impossible facts.
*July 5, 2014*

**Mathematics**

(2 pi r)(35/60)
*July 5, 2014*

**vocabulary**

You are welcome.
*July 5, 2014*

**vocabulary**

Do you not associate imagery with mental pictures?
*July 5, 2014*

**PHYSICS**

Well, force is rate of change of momentum or m A if the mass is constant, so what is the change of momentum? original momentum of driver = 52 *14 = 588 kg m/s final momentum of driver = 0 so change = -588 kg m/s How long did it take? average speed during crash = 14/2 = 7 m/s ...
*July 5, 2014*

**compound interest**

.06/12 = .005 = interest rate/month so multiply by 1.005 every month for 12 months 3500 * 1.005^12 = 3715.87
*July 5, 2014*

**physics**

Exactly, you figured it out. The man would have to pull farther (more parts in the tackle), like maybe eight times as far at 1/5 the weight
*July 5, 2014*

**Soil Chemistry**

http://www.amnh.org/exhibitions/permanent-exhibitions/rose-center-for-earth-and-space/david-s.-and-ruth-l.-gottesman-hall-of-planet-earth/what-causes-climate-and-climate-change/the-atmosphere/greenhouse-gases-a-troposphere-story
*July 5, 2014*

**Soil Chemistry**

most outgoing infrared is absorbed in the troposphere before reaching the stratosphere.
*July 5, 2014*

**Math**

10 (180-alpha) = 360 all the way around the outside 180 - alpha = 36 alpha = 144
*July 4, 2014*

**Calculus**

r = (5/8) x V = (1/3) pi [ (5/8) x ]^2 x V = (1/3) pi (25/64) x^3 etc
*July 4, 2014*

**Algebra**

sketch a graph !!!!
*July 3, 2014*

**physics**

I did #1 #2 potential energy lost = m g h potential energy gained = (1/2) k x^2 for 40 kg 40 * 9.81 * (1+x) = (1/2)(12,000) x^2 solve quadratic for x #3 I have no idea because you did not tell me ratio of bounces
*July 3, 2014*

**ACCOUNTING**

is the sum of your liabilities and ownership equity not your assets? so equity = assets - liabilities
*July 3, 2014*

**chemistry**

P V = n R T T = 16 + 273 V = 10 L = .01 m^3 n of O2 = 51.4/32 n of He = 32.5/4 calculate P of each then add to get total
*July 3, 2014*

**Urgent Calculus Help**

slope is always positive the slope keeps increasing so second derivative is positive
*July 3, 2014*

**Urgent Calculus Help**

Sketch a graph of this function. Then the answers will be obvious.
*July 3, 2014*

**Algebra**

x + (x-6) = 50 2 x - 6 = 50 2 x = 56 x = 28
*July 3, 2014*

**Physics**

m g h is the same small m needs big h Sumo seems to be 20 times as massive as the ball :
*July 3, 2014*

**Physics -- check answers please**

1. ok m g h = 20 * 10 * 2 Joules 2. No. That 400 Joules of potential energy becomes 400 Joules of kinetic energy during the fall. 3. Yes - At maximum stretch the ball stops. The ball is now 2 meters plus x below the starting point where x is the stretch distance down. The ...
*July 3, 2014*

**Social Studies**

NY heeft geen Nederlanders? Ik geloof het niet :)
*July 3, 2014*

**American national government**

separate educational facilities were inherently unequal
*July 3, 2014*

**Physics**

no constant the force increases as the spring stretches F = k x work = k x^2/2 ======================== momentum increases an external force, mg
*July 3, 2014*

**Science**

rot fungus http://en.wikipedia.org/wiki/Wood-decay_fungus
*July 3, 2014*

**Calculus 1**

A = 4 pi r^2 r = D/2 so A = 4 pi D^2/4 = pi D^2 dA/dD = 2 pi D dA/dt = 2 pi dD/dt 1 = 2 pi dD/dt dD/dt = 1/(2pi)
*July 3, 2014*

**arithmetic**

Never buy fish from a farm. Farmed fish is yuucky. Good fish comes from the ocean. lets start with 40 fish the first week 5 die so we have 35 which is 7/8 of original after first week 7/8 or 35 remain then in weeks two and three 3/5* 35 = 21 die so we are left with 35 -21 = 14...
*July 3, 2014*

**Physics (A man in the lift)**

mg down F up mg - F = m a = m g/k mg - jmg = (mg/a)(b+cj) 1-j = (b+cj)/a = 1/k k (1-j) = 1 I do not know what gcd(|a|,|b|,|c|)=1 means so can go no further.
*July 3, 2014*

**us hist**

I was a student in the Netherlands during the Gary Powers U2 incident. Our prestige and President Eisenhower's credibility were terribly damaged even in the Netherlands where the US and Canada were highly respected as the people who came and drove the Germans out.
*July 3, 2014*

**algebra**

6 x^3 - 3 x + 14 x^2 - 7 = 0 3 x (2 x^2 - 1) + 7 (2 x^2-1) = 0 (3x+7)( 2x^2-1) = 0 does that help?
*July 2, 2014*

**Physics**

work in = 44* 13 = 572 Joules which is the increase in kinetic energy
*July 2, 2014*

**Physics**

(a) 208 * 1.91 Joules (b) -154 * 1.91 Joules either add answers to a and b or do (208-154)(1.91)
*July 2, 2014*

**mathematics**

Well, I suppose that is every prime number less than 50 :)
*July 1, 2014*

**Calculus I**

Maybe try this: http://www.youtube.com/watch?v=8CuBoOaiBfA
*June 30, 2014*

**Literature-Help me Ms. Sue**

Yes I agree because then they find out too late
*June 29, 2014*

**Literature-Help me Ms. Sue**

World, warm, wings yes
*June 29, 2014*

**MAT221**

5 y = 8 x + 4 y = (8/5) x + 4/5 so slope is 8/5 so slope of perpendicular is -5/8 form is y = - 5x/8 + b goes through (-4,-4) -4 = -5 (-4)/8 + b b = -4 - 20/8 b = -4 - 5/2 b = -8/2-5/2 = -13/2 so y = - 5 x/8 -13/2 or 8y = -5 x - 52 Now parallel line slope = 8/5 y = 8 x/5 + b -...
*June 29, 2014*

**Physics**

Guess mass of person, say 80 kg guess how many on elevator, say 50 (guess high, we want a strong enough motor) so total mass of people on elevator at one time = 80*50 = 4,000 kg energy change = m g h = 4,000 * 9.8 * 8 = 316,600 Joules divide by 20 seconds ----> 15,688 Watts...
*June 29, 2014*

**Literature-Help me Ms. Sue**

Did you see: " .... I am the grass; I cover all. ..." ?
*June 29, 2014*

**Algebra (Identity Function)**

An identity function returns its argument as its value. x(4) = 4 and y(99) = 99
*June 28, 2014*

**math**

average winning = ( 5+3+2 )/6 = 10/6 net = 10/6 - 2 = -0.33 The house wins, in the end :)
*June 28, 2014*

**Algebra**

quadratic is a parabola with one vertex exponential curves one way like y = e^x curves up sqrt slope becomes smaller and smaller
*June 28, 2014*

**Algebra**

If the difference in x values is constant and the difference in y values is constant then the slope is constant and we have a straight line.
*June 28, 2014*

**Chemistry**

1 dm^3 = 1000 cm^3 = 1 liter so X2CO3 is 15.2 g/liter a liter of this requires 27.5/25 or 1.1 liters of .2 M HCl 1.1 * .2 = .22 mols of HCL X2CO3 + 2 HCl --> 2 XCl + H2CO3 maybe? so we only need .11 mols of X2CO3 .11 mols of X2CO3 weigh 15.2 grams 1 mol X2CO3 weighs 138 ...
*June 28, 2014*

**physics**

By the way, Newton 2 is force = rate of change of momentum F = m A is the simple version but will not work if mass is not constant (rocket or special relativity for example)
*June 28, 2014*

**physics**

Force = rate of change of momentum = m a if mass is constant (7.88 - 8)/.04 = -3 (-5.28+5) /.04 = -7 (0 - 0 ) = 0 so yes m a = .140 (do it in kg) * that a vector
*June 28, 2014*

**physics**

Now wait a minute. If friction wins, you do not move it in any direction. Again in number two, imagine. If you caught the ball at the top, the time is all spent getting up. If you tossed the ball off your roof, most of the time would be spent going down. So d) Time to reach ...
*June 28, 2014*

**physics**

a = change in v/ change in t = -5/1.4 = -3.57 m/s^2 so F = m a = 6(-3.57) = - 21.4 Newtons The friction force will be larger because proportional to the normal force (eight) F = -21.4 (9/6) = -32.1 Newtons friction force F = m a a = -32.1 / 9 = 3.57 m/s^2 so same time, 1.4 ...
*June 28, 2014*

**Physics**

You add the final VERTICAL velocity and the constant horizontal velocity as vectors. You can find the direction with trig if you wish, but the vector components imply direction as well as magnitude. For example V = u i + v j where u is the horizontal velocity component v is ...
*June 28, 2014*

**physics**

The vertical velocity is 0 at the top v = Vi - 9.81 t 0 = 5.25 - 9.81 t t = .535 second to the top h = 0 + Vi t - 4.9 t^2 h = 5.25 (.535) - 4.9 (.535^2) h = 1.40 meter alternate and faster way: (1/2) m v^2 = m g h [ conservation of energy ] h = v^2/2g = 5.25^2/19.6 = 1.40 meter
*June 28, 2014*

**Physics**

sure If you stand on frictionless ice (good luck), your weight is still held up by the ice.
*June 28, 2014*

**Algebra**

multiply by 1.10 every month
*June 28, 2014*

**physics**

How long to fall ? 54 = (1/2) g t^2 108 = 9.81 t^2 t = 3.32 seconds in the air, screaming and wishing for parachute In 3.32 seconds we went 130 meters at constant horizontal velocity u 130 = t (3.32) t = 39.2 m/s so now convert that to miles/hr. (Google). 87.7 miles/hr it says
*June 28, 2014*

**physics**

260,000 m/h * 1 h /3600 s = 72.2 m/s = Vinitial average speed during deceleration = 72.2 / 2 = 36.1 m/s goes 1500 m at 36.1 m/s 1500/36.1 = 41.5 seconds
*June 28, 2014*

**statistics**

3 a Yes, 5/15 = 1/3 3 b just add 5/15 + 3/15 = 8/15 3 c p what are chances of d then a then g ? 5/15 * 7/14 * 3/13 = .03846153 d then g then a ? 5/15 * 3/14 * 7/13 = same etc a then d then g a then g then d g then d then a g then a then d six ways in total, each .03846153 so ...
*June 27, 2014*

**statistics**

for 2 use : http://davidmlane.com/hyperstat/z_table.html
*June 27, 2014*

**NEED HELP WITH CALC**

Yes, you do ds/dt = -.02 s ds/s = -.02 dt ln s = -.02 t + c e^ln s = s = e^(c-.02t) = e^c e^-.02 t e^c = C any old constant in the general solution s = C e^-.02 t when t = 0, s = Si the initial amount so s/Si = e^-.02 t BUT that is P, the fraction remaining so we have part a b...
*June 27, 2014*

**Algebra**

2 sqrt (3) * 4 sqrt (3 * 7) = 8 sqrt (3*3*7) = 8*3 * sqrt (7) = 24 sqrt (7)
*June 26, 2014*

**Physics**

I assume you mean approaching FROM south for example, so moving north momentum 1500 * 9 N = 13500 N momentum 700 * 15 E = 10500 E final mass = 1500 + 700 = 2200 2200 v cos (heading ) = 13500 2200 v sin (heading)= 10500 tan heading = 10500/13500 heading = 37.9 degrees east of ...
*June 26, 2014*

**Physics**

East 5.9 + 2.4 cos 20 = 8.16 north 2.4 sin 20 + .5 = 1.32 d^2 = 8.16^2 + 1.32^2 tan heading = 8.16/1.32 heading east of north = 80.8 deg or heading north of east = 90-80.8 = 9.19 deg
*June 26, 2014*

**physics**

a = change in V/change in time = 40/10 = 4 m/s^2
*June 25, 2014*

**linear algebra**

http://www.gregthatcher.com/Mathematics/GaussJordan.aspx
*June 25, 2014*

**World Geography**

I am very glad Ms Sue answered this because I would have found it necessary to write a book on the subject :) Visions of lateen rigged ships crossing the Indian Ocean from the Spice Islands to East Africa and the Red Sea and caravans trudging overland from the Red Sea to the ...
*June 23, 2014*

**PreCalculus**

2x + 2x + x = 200 5x = 200 Pre - Calculus, sure is.
*June 23, 2014*

**Algebra II**

f(x+h) = 5/(x+h) f(x) = 5/x [f(x+h) - f(x)]/h = [5x -5(x+h)]/[hx(x+h)] = -5 /[x(x+h) } = -5/(x^2+hx) By the way, if you take the limit of that as h--->0 then you are a calculus student and you just found the derivative d/dx (5/x) = -5/x^2
*June 23, 2014*

**Algebra II**

1/(x-a) the domain is all real numbers EXCLUDING x = a where the function is undefined.
*June 23, 2014*

**Suspect typo**

I bet it was 0.4 ohm internal resistance.
*June 23, 2014*

**algebra**

He is asking the same questions over and over again without trying to do them.
*June 22, 2014*

**algebra**

.2 n + 1 n = well, this time it is one of the answers you listed.
*June 22, 2014*

**algebra**

4 n + 7 n = now I did the last one, you finish this one. By the way, none of those answers.
*June 22, 2014*

**algebra**

7 n - 4 n = 30 3 n = 30 n = 10
*June 22, 2014*

**algebra**

-2x + 7x - 2x = -7 + 2
*June 22, 2014*

**Algebra 2**

I think you may mean 5^(n-1) try y = 103 * 5^(n-1) when n = 1, y = 103 * 5^0 = 103 when n = 2, y = 103*5^1 = 103*5 when n = 3, y = 103*5^2 = 103*5*5 etc
*June 22, 2014*

**math**

originally when n = 0, y = 5 after one month, n = 1 and we should have ten so y = 5 * 2^n after 42 months y = 5 * 2^42
*June 22, 2014*

**Probability**

Draw a Venn diagram say we have 100 items 75 are in A or B (25 are outside) 15 are in B 2 of those are also in A (intersection you mean I think) so 13 are exclusively in B That means 75 - 13 = 62 are in A 62/100 = .62
*June 22, 2014*

**Probability**

H H H H H H H T H H T T H T T T T T T T
*June 22, 2014*

**Physics**

a) No true a) the same as b) but impulse = F dt = delta (mv) F dt = 120 N * 10 s = 1200 N s The change of momentum is M (final velocity - 0) so 1200 N s = M (8 m/s) so M = 150 N s^2/m which is 150 kg note N force =Mass (m/s^2) so N s^2/m = M in kilograms 8 m =
*June 21, 2014*

**first what then what ?**

missing input
*June 21, 2014*

**physics**

pi r^2 = area = .25 pi = .785 m^2 area * speed = volume/second .785 m^2 * 1.2 m/s = .942 m^3/s times 3600 seconds /hr = 3393 m^3/hr
*June 21, 2014*

**physics**

(1/2) rho v^2 = rho g h v = sqrt (2 g h ) = sqrt (2*9.81*1.38) which is exactly what would happen if you just dropped a rock that distance or see http://en.wikipedia.org/wiki/Bernoulli%27s_principle
*June 21, 2014*

**physics**

77.9 = 10 log I/10^-12 = log I/10^-11 7.79 = log (I*10^12) 10^7.79 = I * 10^12 6.17 * 10^7 = I * 10^12 I = 6.67 * 10^-5 W/m^2
*June 21, 2014*

**EXCEL 2010 (again)**

I just tried =sum(C3:C9)/7 and it worked
*June 21, 2014*

**physics**

1) do it the same way I did the previous question 1 2) (bottom derivative top - top derivative bottom ) / bottom squared ( x^4 * 0 - 1*4x^3 )/x*8 = - 4 /x^5 3) x^2 cos x - sin x (2x) you finish
*June 20, 2014*

**physics**

1) 0 + 5 + 21 x^2 2) tan x (d cos^2 x /dx)+ cos^2 x d tan x / dx = tan x (-2 sin x cos x) + cos^2 x (sec^2 x) = -2 sin^2 x + 1
*June 20, 2014*

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