Wednesday

July 30, 2014

July 30, 2014

Total # Posts: 17,562

**math**

y = (3/5) x + b -4 = (3/5)(2) + b b = -20/5 - 6/5 = -26/5 y = (3/5) x - 26/5 5 y = 3 x - 26

**math**

m = (-5 - 1)/(2-4) = 3 m' = -1/m = -1/3 y = -x/3 + b find point on original line halfway between x = (4 +2 )/2 = 3 y = (1 - 5)/2 = -2 so -2 = -3/3 + b b = -1 so y = -x/3 - 1 3 y = -x - 3

**business**

8%/4 = 2% per quarter so every three months multiply by 1.02 25 * 1.02^n = 45 1.02^n = 1.8 n log 1.02 = log 1.8 n = 29.68 quarters or 7.42 years

**Urgent Calculus Help 2**

You are welcome.

**Urgent Calculus Help 2**

dy/dx = 6x d/dx [ln(x+4)]+ 6 ln(x+4) = 6 x /(x+4) + 6 ln(x+4) so at x = 2 dy/dx = slope = m = 12/ln(6) + 6 ln (6) but ln (6) = 1.79 so use that to find the slope m then we have y = m x + b and we know m find y at x = 2 y= 12 (1.79) = 21.5 so use that 21.5 = 2 m + b we know m, ...

**Urgent Calculus Help**

h' = df/dg * dg/dx at x = 2 dg/dx = -2 and g = 7 df/dg at g = 7 = -8 so -8 * -2 = + 16 that is how, you do the next

**ph**

For heaven's sake do what Ms Sue suggested. For me pH means acid or base. Stop wasting teacher time. We are volunteers here and you need someone who does prescriptions, not a physicist or historian. I have a sneaking suspicion you mean 250 milligrams every 8 hours for 7 da...

**physics**

soft spring ---> slower vibration which means longer period. You knew that. 2 pi sqrt (m/k)

**physics**

Northeast 65 sqrt 2 = 91.9 N

**Physics**

Potential energy drop = m g h =90*9.81*100 = 88,290 Joules Kinetic energy = (1/2) m v^2 = 45(900) = 40,500 Joules so loss to heat = difference = 47,790 Joules

**Science**

It means that there is 1/4 mol of oxalic acid in every liter of the stuff and the rest is water.

**TYPO**

g = -32 ft/s^2 it is -32/2 which is -16 and h(2) = (1/2)(-32) t^2 + 36 t + 4 h(2) = -16 (2)^2 + 36 (2) + 4 h(2) = -64 + 72 + 4 h(2) = 12 feet

**Algebra**

outside dimensions are 10+2w and 16+2w total area = 160 + 52 w + 4 w^2 pool area = 160 so sidewalk area = 4 w^2 + 52 w = 155 4 w^2 + 52 w -155 = 0 (2w-5)(2w+31) = 0 w = 5/2 = 2.5 ft

**Physics**

330 cos 15 = Vwest - 65 330 sin 15 = Vsouth so Vwest = 383.7 km/h Vsouth = 85.4 km/hr Vplane = sqrt (383.7^2+85.4*2) tan angle south of west = 85.4/383.7

**Algebra**

NO !!!!!! a straight line with y = m x + b with m negative so negative slope would satisfy answer A but the slope of these points is NOT constant

**Algebra**

try y = k/x for (2,30) 30 = k/2 k = 60 for (5,12) 12 = k/5 k = 60 sure enough x*y always = 60 (answer C)

**Algebra**

slope = change in y / change in x the change in y will not be constant unless you pick evenly spaced x values (the same changes in x) if change in y is constant for evenly spaced x values then the slope is constant so it is a straight line.

**phys**

Yes, assuming they are the same mass.

**phys**

V = x^3 dV = 3 x^2 dx dV/V = 3 x^2 dx/x^3 = 3 dx/x ah ha, C

**algebra**

well, look after a year .5*1.06 + .5*1.08 = 1.07 1 * 1.07 = 1.07 look after 5 years .5(1.06)^5 + .5(1.08)^5 = 1.403776827 1.07^5 =1.402551731 less look after 20 years .5*1.06^20 + .5*1.08^20 = 3.9340463 1.07^20 = 3.869684462 less Tasha wins because the 8% half makes the Tasha ...

**algebra**

I do not see the statements .5*(1.06)^n + .5(1.08)^n compared to 1 * (1.07)^n

**Algebra**

You are welcome.

**Algebra**

Well, that is a parabola. Where is the vertex? -16 t^2 + 48 t = h 16 t^2 - 48 t = -h t^2 - 3 t = -(1/16)h t^2 - 3 t + 9/4 = -(1/16)h + 9/4 (t - 3/2)^2 = -(1/16)(h - 36) ah ha, hits the vertex at the top when t = 1.5 seconds and h = 36 feet

**calculus**

y = -4 t^2 -t - 6 slope = dy/dt = -8 t - 1 at t = 8, slope = -65 so our tangent line is of form y = -65 t + b to find b, we need a point on the line when t = 8, y = -4(64) -8 -6 = -270 so use that point (8, -270) to find b -270 = -65(8) + b b = 250 so in the end y = -65 t + 250

**Math**

divide (-4/5) by two so -2/5 square that 4/25 add it b^2 -(4/5) b + 4/25 which is (b-2/5)^2

**English Essay Part 2**

Cynthia, I am so happy **that** you **** moved back to Athens. I spoke to your mom the other day.*** She told me **that** you were looking for a job. ** I know you *** worked as a cashier and a sales clerk **recently**. Therefore, I have a very special offer for you. **** I wo...

**Math**

299

**Electro 1**

r = R1 R2 / (R1+R2) = 1.95*.05 /2 = .04875 In other words if connected in parallel, the .05 resistor carries practically all the current. V = 50 *.04875 = 2.4375 volts i through .05 = 2.4375/.05 = 48.75 amps i through 1.95 = 2.4375/1.95 = 1.25 amps

**Electro 1**

I assume the wires are in series with the load, leading to the + and - sides of the power source. total R = 6.5 ohms i = V/R = 119.6 / 6.5 = 18.4 amps V = i R = 18.4 * 6 = 110.4 volts across 6 ohm load V = i R = 18.4 * .25 = 4.6 volts across each of the two wires.

**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

**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 gi...

**algebra**

anything at all to the zero power is one.

**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...

**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

**PHYSICS**

You did not ask any question.

**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

**PHYSICS**

see below

**PHYSICS**

Hey, do it the same way.

**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

**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

**Math**

x = 1 and y = 10 -->1-.1 = .9 try others x = 2 and y =9 --> 1/2 - 1/9 see?

**SCIENCE**

70 = m v^2/r 70 = 70 (35)^2 /r r = 35^2 = 1225 http://www.jiskha.com/m

**Algebra**

do you mean (8n+8) ?????

**Algebra**

y - -1 (x^2 - 8 x + 16) + 2 y = -x^2 + 8 x - 16 + 2 y = -x^2 + 8 x - 14

**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.

**Mathematics**

(2 pi r)(35/60)

**vocabulary**

You are welcome.

**vocabulary**

Yes

**vocabulary**

Do you not associate imagery with mental pictures?

**vocabulary**

No.

**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 i...

**compound interest**

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

**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

**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

**Soil Chemistry**

most outgoing infrared is absorbed in the troposphere before reaching the stratosphere.

**Math**

10 (180-alpha) = 360 all the way around the outside 180 - alpha = 36 alpha = 144

**Calculus**

r = (5/8) x V = (1/3) pi [ (5/8) x ]^2 x V = (1/3) pi (25/64) x^3 etc

**Algebra**

sketch a graph !!!!

**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

**ACCOUNTING**

is the sum of your liabilities and ownership equity not your assets? so equity = assets - liabilities

**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

**Urgent Calculus Help**

slope is always positive the slope keeps increasing so second derivative is positive

**Urgent Calculus Help**

Sketch a graph of this function. Then the answers will be obvious.

**Algebra**

x + (x-6) = 50 2 x - 6 = 50 2 x = 56 x = 28

**Physics**

m g h is the same small m needs big h Sumo seems to be 20 times as massive as the ball :

**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 tota...

**Social Studies**

NY heeft geen Nederlanders? Ik geloof het niet :)

**American national government**

separate educational facilities were inherently unequal

**Physics**

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

**Science**

rot fungus http://en.wikipedia.org/wiki/Wood-decay_fungus

**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)

**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...

**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.

**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.

**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?

**Physics**

work in = 44* 13 = 572 Joules which is the increase in kinetic energy

**Physics**

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

**mathematics**

Well, I suppose that is every prime number less than 50 :)

**Calculus I**

Maybe try this: http://www.youtube.com/watch?v=8CuBoOaiBfA

**Literature-Help me Ms. Sue**

Yes I agree because then they find out too late

**Literature-Help me Ms. Sue**

World, warm, wings yes

**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 -...

**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...

**Literature-Help me Ms. Sue**

Did you see: " .... I am the grass; I cover all. ..." ?

**Algebra (Identity Function)**

An identity function returns its argument as its value. x(4) = 4 and y(99) = 99

**math**

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

**Algebra**

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

**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.

**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 gra...

**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)

**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

**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 ma...

**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 sec...

**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 th...

**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

**Physics**

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

**Algebra**

multiply by 1.10 every month

**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

**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

**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 m...

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