Monday

January 26, 2015

January 26, 2015

Total # Posts: 20,417

**math**

x y z 4 y z y>z 4 + y + z = 6 y + z = 2 since y>z y = 2 and z = 0 4 2 0
*September 16, 2014*

**Pre-Calculus**

a) so use -3 for x (-3)^2 + 9 = 9+9 = 18 b) now use -2 for x (-2)^2 + 9 = 4 + 9 = 13
*September 16, 2014*

**Calculus I**

dL = a Lo dT L = a Lo T + constant when T = 0, L = Lo so L = (a Lo) T + Lo To is y (or in this case L)axis intercept (a Lo) is slope
*September 16, 2014*

**Curriculum**

The average dictator would name the gerbil :)
*September 16, 2014*

**Math**

A number and its absolute value are equal. SO IT IS POSITIVE OR ZERO if you subtract 2 from the number, the new number and its absolute value are not equal. IT GOT NEGATIVE WHEN WE TOOK 2 FROM IT, SO IT IS BETWEEN ZERO AND TWO 1.9999999999999999999999999999 :)
*September 16, 2014*

**Curriculum**

Way to go Daniela !!!! Much better answers today !
*September 16, 2014*

**Geography**

GDP is entirely financial and may say nothing about how well the residents live. For example a country with huge natural resources such as gold mines may have a high GDP but only a few rich people and the vast majority uneducated and underfed. HDI takes into account how well ...
*September 16, 2014*

**Math**

and for the third time 25 minutes
*September 16, 2014*

**Math**

still 25 minutes
*September 16, 2014*

**Math**

3/5 * 5/3 = 1 entire task :) 15 * 5/3 = 25 minutes
*September 16, 2014*

**chemistry**

Ice water remains at 0 deg C until all is melted. In other words , yes you are correct.
*September 16, 2014*

**Urgent Spanish Check**

gato ends with o
*September 16, 2014*

**Physics**

tourist runs d at 5.56 bear runs (d+26.6) at 7.69 same time for both time = (d+26.6)/7.69 = d/5.56 solve for d
*September 16, 2014*

**maths**

76-47 = 29 47-29 = 18 29-18 = 11 18-11 = 7 11-7 = 4 7 -4 = 3 <--------
*September 16, 2014*

**Physics**

pick some times that meet the criterion north for 30 seconds, south for 10 seconds , total time = 40 seconds distance north from start = 25*30 then back 32*10 total distance north (displacement vector, not distance traveled) = 25*30 - 32*10 so Vaverage = (25*30 - 32*10)/40 = (...
*September 16, 2014*

**Physics**

a) 515/229 b) average speed = (0 + final speed)/2 = answer to part (a) in other words answer to b = twice answer to a c) a = change in velocity/change in time = answer to part b /229 seconds
*September 16, 2014*

**Physics**

Vi = 2.53 Hi = 5.82 0 = Hi + Vi t - 4.9 t^2 4.9 t^2 - 2.53 t - 5.82 = 0 solve quadratic for t eg : http://www.mathportal.org/calculators/polynomials-solvers/polynomial-roots-calculator.php
*September 16, 2014*

**Coordinate Algebra**

y = -3 x + b 4 = -3 (5) + b 4 = -15 + b b = 19 y = -3 x + 19
*September 16, 2014*

**Algerbra**

http://davidmlane.com/hyperstat/z_table.html
*September 16, 2014*

**Social Studies**

I agree with you.
*September 16, 2014*

**Social Studies**

These tricky double negative questions are exasperating.
*September 16, 2014*

**Social Studies**

So C is the answer. Farmers were NOT allowed to own slaves.
*September 16, 2014*

**Social Studies**

the trustees prohibited Negro slavery, for they believed that this ban would encourage the settlement of "English and Christian" people.
*September 16, 2014*

**Social Studies**

No, It was charitable, to help the poor !!!!! One of the reasons they prohibited slavery was to avoid large plantations as had infested South Carolina !!!
*September 16, 2014*

**algebra**

ok, sure, you paid 10 for the right to buy tickets (admission to the fair grounds?)
*September 16, 2014*

**differential calculus**

tan A = h/50 sec^2 A * dA/dt = (1/50) dh/dt dA/dt = (4/50)cos^2 A at h = 50, cos A = .707 and cos^2 A = 1/2 dA/dt = 4/100
*September 16, 2014*

**differential calculus**

p v^1.3 = k p d/dt (v^1.3) + v^1.3 dp/dt = 0 1.3 p v^.3 dv/dt + v^1.3 dp/dt = 0 1.3 p dv/dt = - v dp/dt 1.3 dv/dt /v = - dp/dt /p
*September 16, 2014*

**Algebra**

that last number = (d/2)^2 so 64 = d^2/4 d^2 = 4 * 64 d = 2*8 d = 16 like (x+8)(x+8) then the second one d^2/4 = 49/4 so d = 7 like (x+7/2)(x+7/2) = x^2 + 7 x + 49/4
*September 15, 2014*

**geography**

HUH? They are perpendicular to each other. Meridians run north South and equator runs East west. There is only one equator, around the middle between north and south poles. There are lots of meridians stretching from north pole to south pole and just one is selected (through ...
*September 15, 2014*

**Physical Science**

subtract
*September 15, 2014*

**Chemistry**

every .001 mol Ca(OH)2 needs .002 mol of HCl so we have .002 mol in 25*10^-3 liters .002/.025 = .08 mol/liter
*September 15, 2014*

**Chemistry**

N 14 g/mol H 1 g/mol NH3 is therefore 17 g/mol, 2NH3 is 34 N2 is 28 g/mol every 2 mol of NH3 requires 1 MOL OF N2 so every 34 g of NH3 requires 28 g of N2 so finally 325 g NH3 (28 N2/34 NH3) = 268 g N2
*September 15, 2014*

**Chemisty**

Mg --> 24.3 g/mol 2 O --> 32 2 H --> 2 sum = 58.3 g/mol 17.8 g * (1 mol/ 58.3 g) = .305 Mol ======================================== 123 + 273 = 396 deg K 468 + 273 = 741 deg K P1 V1/T1 = n R = P2 V2/T2 V2 = V1 (P1/P2) (T2/T1) V2 = 20.46 (1.35/1.35) (741/396)
*September 15, 2014*

**Math**

length of ramp is hypotenuse = c length along floor is adjacent = a cos (angle) = a/c
*September 15, 2014*

**History**

Whew :)
*September 15, 2014*

**History**

the mission included men with skills or training in ******geology******, botany, zoology, and ethnology as well as a naturalist, an artist, and a topographer.
*September 15, 2014*

**Can't follow links, help please**

From http://digital.library.okstate.edu/encyclopedia/entries/P/PI007.html Many of the objectives of this expedition were fulfilled. In 1806 Wilkinson ordered Pike and an ill prepared party of twenty-two to seek the headwaters of the Arkansas and Red Rivers, obtain the return ...
*September 15, 2014*

**Physics**

v = 5 - 9.8 t 0 = 5 - 9.8 t t = 5/9.8 = .51 seconds to top where v = 0 average speed going up = 5/2 = 2.5 m/s h = 1.5 + 2.5 * .51 = 2.78 meters (a) no way (b)The same speed it will have if dropped from the top of the wall and landing on a platform 1.5 m high 3.95 - 1.5 = 2.45 ...
*September 15, 2014*

**Math**

Yes.
*September 15, 2014*

**Math**

27/9 =
*September 15, 2014*

**college algebra**

.08 x + .04(29,000-x) = 1680
*September 15, 2014*

**general knowledge**

I bet you mean 15 sept in which case type: TODAY
*September 15, 2014*

**8th grade math**

5^2/5^5 = 1/5^3 = 5^-3 = 1/125
*September 15, 2014*

**Physics**

v^2/r
*September 15, 2014*

**physics**

k Q1Q2/r^2
*September 15, 2014*

**Physics**

(v+c)19.8 = (v-c)21 and (v+c)19.8 = 208
*September 15, 2014*

**Algebra 2**

5 n + 25 q = 620 25 n + 5 q = 970
*September 15, 2014*

**Statics**

102
*September 15, 2014*

**World History (Ms. Sue)**

Pretty good.
*September 15, 2014*

**Math using quadratic equation**

I suspect typos and there is no quadratic involved as it is stated. v = passenger train speed (v - 12) = freight train speed (v-12)t = 65 v t = 165 so 65/(v-12) = 165/v 65 v = 165 v - 1980 100 v = 1980 v = 19.8 mph v-12 = 7.8
*September 15, 2014*

**Math using Quadratic equation**

s^2 = 196 s = 14 check : 12 * 14 = 196
*September 15, 2014*

**Curriclum**

You are right !
*September 14, 2014*

**math**

-32 - 13
*September 14, 2014*

**physics**

average speed during deceleration = 2.5*10^3 m/s time is then 4 m/2.5*10^3 m/s = 1.6*10^-3 seconds to stop a = - 5*10^3/1.6*10^-3 = -3.125*10^6 m/s^2 = - 3,125,000 m/s^2:)
*September 14, 2014*

**physics**

u = 75 cos 57.3 so t = 21.5 /(75 cos 57.3) Vi = 75 sin 57.3 h = Vi t - 4.9 t^2 answer = h-11
*September 14, 2014*

**Physics**

I just answered this a few minutes ago. I used the rest mass here because .3*.3 is just about .1 and not worth calculating beta. However look at the problem below this one if you want to do the relativistic problem. Posted by Paul on Sunday, September 14, 2014 at 4:30pm. ...
*September 14, 2014*

**Physics**

m at .77 c beta = .77 sqrt (1 - beta^2 )= sqrt(.4071) = .638 so m' = 1/.638 = 1.57 kg (1/2)m' v^2 = 4.19*10^16 Joules
*September 14, 2014*

**Physics**

(1/2) m v^2 = 5,000 * (.3*3*10^8)^2 = 5*10^3 * .81 * 10^16 = 4.05 * 10^19
*September 14, 2014*

**Pre-Calculus**

http://www.mathportal.org/calculators/polynomials-solvers/polynomial-roots-calculator.php
*September 14, 2014*

**math**

L = (3w-5) L w = 782 (3w-5)w = 782 3 w^2 -5 w -782 = 0 (3w+46)(x-17) =0 x = 17 or x = -46/3 use x = 17 then L = 782/17 = 46
*September 14, 2014*

**math**

over in the triangle between shadows we have a 32 degree angle. At the other end of our 60 meters we have a 180=54 = 126 degree angle. Therfore up at the top of that triangle we have a 180 - 32 - 126 = 22 degree angle law of sines for long hypotenuse ray call it x sin 126/x = ...
*September 14, 2014*

**alg 2**

If x > -8 y < x+8 - 4 or y < x+4 If x <-8 y < -(x+8) - 4 or y <-12 -x
*September 14, 2014*

**Physics**

I answered this a few minutes ago (29.5+15.5)/(5*10^-3)
*September 14, 2014*

**history pt 2**

Romans wanted first of all control of Sicily. Carthaginians wanted the Romans to stop trying to take over their trade routes and territory.
*September 14, 2014*

**Physics**

3/x = 2/(x-5) 2 x = 3 (x-5) 2 x = 3x-15 x = 15
*September 14, 2014*

**Pre-Calculus**

Hey, I did this down below.
*September 14, 2014*

**Pre-Calculus**

5/4 +/- 2 i sqrt(11)
*September 14, 2014*

**Pre-Calculus**

*************_2x^2___________-1x+1 (3x^2 + 13) / 6x^4-3x^3+29x^2+0x+0 **************6x^4_____+26x^2_____ *******************-3x^3+3x^2 +0x+0 *******************-3x^3______-13x ************************ +3x^2+13x+0 ************************ +2x^2____+13...
*September 14, 2014*

**history**

Yes
*September 14, 2014*

**Physics**

change in velocity/change in time = (15.5 +29.5)/5*10^-3 if the second part asks for the average force, multiply by the mass
*September 14, 2014*

**Physics**

how far does it fall in .19 s ? delta h = (1/2) g t^2 = 4.9*.19^2 = .177 meter = 17.1 cm u = 14 d = u t = 14 *.19 = 2.66 m to board
*September 14, 2014*

**Pre-Calculus**

18 x^2 - 6 x +1 = 0 x = [6 +/- sqrt ( 36 - 72) ] /36 = [(1/6) +/- sqrt(-1) ] = 1/6 +/- 1 i
*September 14, 2014*

**Physics**

power = i V 400 = i (120) i = 3.33 rms i peak = i rms * sqrt 2 = 4.71 amps peak
*September 14, 2014*

**Physics**

12 V * 5.9 amps * time in seconds = 4.8*10^3
*September 14, 2014*

**Science**

v = Vi + a t 0 = 100 - 5 t t = 20 seconds
*September 14, 2014*

**Math**

of course if you can not split a pack, it is 63*5 = 315 apples
*September 14, 2014*

**Math**

sells for 2.40/5 = .48 per apple .48 x = 150 x = 313 apples or 63 packs
*September 14, 2014*

**physics**

goes 168 *2 meters in 1 second so 336 m/s that day there.
*September 14, 2014*

**math**

hits x axis at 3 so goes through (3,0) y = 2 x + b 0 = 2 (3) + b b - -6 y = 2 x - 6
*September 14, 2014*

**Physics - Grade 10**

No motion, no work.
*September 14, 2014*

**Math**

hyperbola centered at x =12/2 = 6 hits x axis at (5.5 , 0) and (6.5 , 0) (x-6)^2/a^2 - y^2/b^2 = 1 2 a = 1 a = 1/2 a^2 = 1/4 4 (x-6)^2 - y^2/b^2 = 1 center to either focus = 4 =sqrt(a^2+b^2) so 16 = 1/4 + b^2 b^2 = 16 - 1/4 = 63/4 4(x-6)^2 - 4y^2/63 = 1 (x-6)^2 - y^2/63 = 1/4
*September 14, 2014*

**Whoops**

Sorry about that.
*September 13, 2014*

**Math**

4*4 = 16 compounds 8.5/4 = 2.125% = .02125 1.02125^16 = 1.39995 * 25,000 = 34,998.80 final value - 25,000 = 998.80 interest
*September 13, 2014*

**y is positive down?**

If so then melon trajectory u = 12.1 forever x = 12.1 t so t = x/12.1 v = g t = 9.81 t y = 4.9 t^2 so y = 4.9 x^2/146 = .0335 x^2 y^2 = .00112 x^4 when they hit 14.9 x = .00112 x^4 x^3 = 13303 x = 23.7 y = .0335 x^2 = 18.8
*September 13, 2014*

**Algebra1**

You are welcome.
*September 13, 2014*

**Algebra1**

1x-3x = -2x -4y-3y = -7y 2z+2z = 4z so -2x-7y+4z
*September 13, 2014*

**geometry**

ok, you are welcome.
*September 13, 2014*

**geometry**

4.4 the shape and size are not changed by turning it, so congruent. 5.5 - no idea without seeing it.
*September 13, 2014*

**math**

You are welcome.
*September 13, 2014*

**math**

turn slide translation (same question as 2.2 above)
*September 13, 2014*

**physics**

3.9 E5 km
*September 13, 2014*

**physics**

The point is that 20 min = 1/3 hour
*September 13, 2014*

**physics**

3 km/20 min = 3 km / (1/3)hr = 9 km/hr
*September 13, 2014*

**Math**

93542
*September 13, 2014*

**physics**

v = Vi - g t 0 = 20 - 9.81 t t = about 2 seconds
*September 13, 2014*

**physics**

divide by .707 which is 1/sqrt 2
*September 13, 2014*

**physics**

R the same i2 = 2 i1 so i2^2 R = 4 i1^2R 4 * 22 = 88 Watts
*September 13, 2014*

**physics**

10 Joules is correct to 2 significant figures. Try 10. or 10.0
*September 13, 2014*

**physics**

Hey, I took the course and already know how to do these, now you try and ask us if you get stuck showing where you got stuck.
*September 13, 2014*

**physics**

645 * 590 = 380,550 W or 381 kW Ke = (1/2)m v^2 = (1/2)(4.5*10^4)(900) = 2025*10^4 = 2.025*10^7 Joules energy needed = (2.025/.91)10^7 = 2.225 * 10^7 Joules 3.8055*10^5 t = 2.225*10^7 t = .585*10^2 = 58.5 seconds, about a minute a = delta v/delta t = 30/58.5 = .513 m/s^2 ...
*September 13, 2014*

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