Saturday

August 23, 2014

August 23, 2014

Total # Posts: 17,989

**algebra**

x = 3 , y = 2 is the intersection
*June 13, 2014*

**algebra**

http://www.wolframalpha.com/input/?i=plot+y%3D2x-4+and+y%3D5x-13
*June 13, 2014*

**algebra**

https://www.wolframalpha.com/input/?i=plot+y%3D2x-4+and+y%3D5x-13
*June 13, 2014*

**Math**

You are welcome.
*June 13, 2014*

**Math**

anything to the 0 power is 1 anything divided by itself is one unless the denominator is zero.
*June 13, 2014*

**typo**

plus or minus 60 x
*June 13, 2014*

**maths**

natural log (base is e) is usually written ln(x) ln (e^x) = x ln e but ln e = 1 so ln (e^x) = x * 1 = 1 argument is somewhat circular but I do not know what else to say.
*June 13, 2014*

**algebrahave i done this right**

You are welcome :)
*June 13, 2014*

**algebrahave i done this right**

mean = 1770/27 = 65.56 mode is clearly 70 if there are ten of them median, there are 10 below 70 and 4 above 70 so the median is in your 70 group, yes the range is from 40 to 90 so yes 50
*June 13, 2014*

**algebrahave i done this right**

I do not understand. is your data set 2 90 s 5 80 s 10 70 s etc? if so I count 27 data points not 25
*June 13, 2014*

**typo?**

the height is 5 meters? do you mean the length is maybe 50 meters? anyway perimeter = 2*L + 2*W area = L * W
*June 13, 2014*

**PHYSICS**

centripetal acceleration Ac = R omega^2 R = earth radius at equator but R = 0 at poles rotation of earth tries to throw you off into space but gravity holds you on earth. g = 9.81 - R omega^2
*June 13, 2014*

**Algebra please can you ck my work**

check my earlier answers things are getting worse except for the 152 ---512 typo
*June 13, 2014*

**algebra/please can you ck my answers**

log base ten of 16.9 = 1.23 log2 (512 not 152) = 9 because base^log x = x 2^9 = 512 log 1 = 0 for any base at all because any base^0 = 1 log base 10 = log10(.046) = -1.34 that is NEGATIVE 1.34
*June 13, 2014*

**PHYSICS**

LOL, try it with anything on your desk, gently ! it will experience BOTH angular acceleration (spin) and linear acceleration.
*June 13, 2014*

**Algebra**

You are welcome.
*June 13, 2014*

**Algebra**

40/1.6 = n/5 so n = 200/1.6 = b) 150 * 1.6/40 =
*June 13, 2014*

**USA Colonists History**

http://www.mainememory.net/sitebuilder/site/283/page/546/display
*June 13, 2014*

**USA Colonists History**

... or fresh water :)
*June 13, 2014*

**USA Colonists History**

The English had a serious problem finding tall white pines for masts in Europe, particularly when they were having trouble with countries around the Baltic Sea. I do not do land, sorry.
*June 13, 2014*

**USA Colonists History**

catch cod, sell it in the West Indies and Europe catch beavers, sell fur in Europe
*June 13, 2014*

**Physics**

1 * 605 * 10^-9 * .85 / 5.4 *10^3 = 95 * 10^-6 m = .095 mm
*June 13, 2014*

**Physics**

yes, up means higher frequency
*June 13, 2014*

**Physics**

yes
*June 13, 2014*

**algebra**

1 and 2 that is 2/6 or 1/3 450/3 = 150
*June 13, 2014*

**Physics**

wait a minute, add the weight of the ball!. 10 + 10*9.81 = 108 N
*June 13, 2014*

**Physics**

You are welcome.
*June 13, 2014*

**Physics**

Force * time = impulse = change in momentum T (10) = 10 * 10 T = 10 N which by the way is about the weight of the ball on earth. I think it would take longer.
*June 13, 2014*

**physics**

distance = speed * time with no force in horizontal direction 65 = 14 t t = 4.64 seconds in the air In the vertical direction it simply falls a distance h h = (1/2) g t^2 = 4.9 (4.64^2) h = 106 m
*June 13, 2014*

**Physics**

80 cal = 335 joules so Lf = 335 Joules / .001 kg - 335,000 Joules/kg potential energy = m g h m g h = m (335,000) 9.81 h = 335,000 h = 34,149 meters
*June 13, 2014*

**PHYSICS**

2 pi radians every 60 seconds 2 pi/60 = pi/30
*June 13, 2014*

**Physics**

call side of square = 1 look at components along diagonal 2(1.1 *1.1 /1^2)cos 45 = 1.1 q/(sqrt2)^2 cos 45 = 1/sqrt 2 2(1.1) = q/sqrt 2 q = 2.2 sqrt 2
*June 13, 2014*

**Physics**

F = m a F = E q same for both where q = electron charge, + for proton, - for electron m = mass electron for electron m = mass proton for proton
*June 13, 2014*

**Science**

Something you do to get something going. https://www.google.com/search?q=stimulus+definition&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=sb
*June 12, 2014*

**Math**

pi d^2/4 h (3.14 * 7.4*7.4 * 2.4 ) / 4
*June 12, 2014*

**MATH**

integral of e^(Lx)dx = (1/L) e^(Lx) + c
*June 12, 2014*

**Physics**

F = m a = -kx if x = A cos w t v = dx/dt = -Aw sin w t a = d^2x/dt^2 = -A w^2 cos w t = -w^2 x so -m w^2 x = -k x w^2 = k/m w^2 = 210/3 = 70 w = sqrt(70) = 8.37 when |x| = .23 , |v| = .72 .23 = A cos 8.37 t .72 = -A (8.37) sin 8.37 t so cos 8.37 t = .23/A sin 8.37 t = .086/A ...
*June 12, 2014*

**Physics**

North south problem 7.5 Vn = 4.5 (8.5 cos 30) -7.5(6.5 sin 20) East west problem 7.5 Ve = 4.5(8.5 sin 30) +7.5(6.5 cos 20)
*June 12, 2014*

**math equation**

1/3 + 1/4 = 4/12 + 3/12 = 7/12 right 12/12 - 7/12 = 5/12 right he has 5/12 left so 5/12 of salary = 400 multiply both sides by 12/5, the inverse 60/60 of salary = (12/5) * 400 = 12 * 80 = 960
*June 12, 2014*

**physics**

F = k x 10.5 = k (.72 k = 10.5 N/.72 m
*June 12, 2014*

**Science(electric circuits)**

Maybe the total current is the sum of the currents through the individual paths.
*June 12, 2014*

**Physics**

1/Req = 1/1 + 1/2 + 1/4 1/Req = 4/4 + 2/4 + 1/4 = 7/4 so Req = 4/7 The voltage is the same across all elements in parallel i for the 4 ohm = 6/4 = 1.5 amps P = i V or i^2 R = 1.5 * 6 or 2.25 * 4 = 9 watts
*June 12, 2014*

**Physics**

voltage across resistor = i R = 1.5*5 = 7.5 Volts voltage loss to internal resistance = 1.5 * .15 = .225 volts total voltage = 7.5 + .225 = 7.725 Volts
*June 12, 2014*

**physics**

.2 kw * 10 = 2 kw hr per day times 365 = 730 kw hr per year times .15 dollar/kw hr = $109.50 per year = $110 rounded to nearest dollar
*June 12, 2014*

**Science(electric circuits)**

If elements are in parallel, each sees the same voltage and the current is split up between them.
*June 12, 2014*

**physics**

100 * (.4/.05) = 800 N arms 0.4 meters long? That is one big nut cracker.
*June 12, 2014*

**physics**

F * 10 = 600 * 4 F = 600 * .4 = 240 N if you tried to lift at the other end F2* 10 = 600 * 6 F2 = 360 N
*June 12, 2014*

**physics**

http://www.jiskha.com/display.cgi?id=1402590278
*June 12, 2014*

**Science(electric circuits)**

voltages across individual elementsd add in a series circuit.
*June 12, 2014*

**Science(electric circuits)**

If you take one element out of a series circuit, no current can flow and all elements lose power. Remember the old Christmas tree lights that were wired in series? If one went out, they all went out.
*June 12, 2014*

**Science(electric circuits)**

If devices are wired in series, the same current goes through each of them.
*June 12, 2014*

**science (help)**

water, fresh and salt.
*June 12, 2014*

**Algebra**

clark + clark + 5 = 33 2 clarks = 28 clark = 14 so shelly = 19
*June 12, 2014*

**Math**

6x,xx5 so 11 + 3 x = 23 3 x = 12 x = 4 64,445
*June 12, 2014*

**Physics**

south 7-3 = 4 east 7-4 = 3 d = sqrt (9+16) = 5km tan theta = 3/4 where theta is angle east of south theta = 36.9 deg east of south or 180 -36.9 = 143.1 on your compass clockwise from north
*June 12, 2014*

**Physics**

no idea, depends on coef of friction between road and man's shoes.
*June 12, 2014*

**physics**

Take moments about foot of ladder of length L 200 (L/2) sin 30 = F L sin 60 50 = F sin 60 F = 57.7 N
*June 12, 2014*

**Math**

area of layer = pi D^2/4 = 3.14 (49/4) = 38.465 in^2 8 layers = 307.72 in^2 divide by 55 5.6 batches so make 6
*June 12, 2014*

**Introductory Algebra**

Ah, what was that exchange rate ?
*June 11, 2014*

**algebra**

3 pounds of tin = 3(c+2) dollars 7 pounds of copper = 7 c dollars 10 pounds of bronze = 38.50 dollars so 7 c + 3 c + 6 = 38.5 c = 3.25 dollars per pound for copper so c+2 = 5.25 dollars per pound for tin
*June 11, 2014*

**math**

infinity
*June 11, 2014*

**Math help!**

let z = ln(5x) d/dx tan z = sec^2 z dz/dx but dz/dx = d/dx ln(5x) = (1/5x)5 = 1/x so (1/x)sec^2(ln(5x))
*June 11, 2014*

**Math help!**

I have a hunch you mean: (x^4+x^2+1)/(x^2+1) (bottom d top - top d bottom)/bottom squared [ (x^2+1)(4x^3+2x) -(x^4+x^2+1)(2x)]/(x^2+1)^2 [4x^5+6x^3+2x-2x^5+2x^3+2x]/(x^4+2x^2+1) [2x^5+8x^3+4x]/(x^4+2x^2+1
*June 11, 2014*

**Math**

You are welcome :) By the way, the only tricky thing on this general subject is that if you multiply (or of course divide) both sides by a negative number, reverse the direction of the arrow.
*June 11, 2014*

**Math**

Does your symbol mean greater than or equal to? If so: y - 6 >/= 12 add 6 to both sides y >/= 18
*June 11, 2014*

**math please help!**

d/dx [e^-(3x) ] [ sin (4 x) ] = [e^-(3x) ] d/dx [ sin (4 x) ] + [ sin (4 x) ] d/dx [e^-(3x) ] = [e^-(3x) ][4 cos (4x) ] + [ sin (4 x) ][ -3 e^-(3x) ] = e^-(3x)[ 4 cos (4x) -3 sin (4x) ]
*June 11, 2014*

**HISTORY**

Well, we agree about Atlanta to the sea :)
*June 11, 2014*

**HISTORY**

12. Check your MAP !
*June 11, 2014*

**HISTORY**

Lincoln put off the proclamation until the Union won a battle, Antietam.
*June 11, 2014*

**HISTORY**

9. agree 10. The border states mostly allowed slavery. Therefore there were by definition differences of opinion on the subject in the Union camp.
*June 11, 2014*

**HISTORY**

( I was born in Maryland :)
*June 11, 2014*

**HISTORY**

NO !!!!!!!!!!!!! Virginia was a free state that surrounded Washington, D.C., on the west and south. *** NO !!!!!!!!!!!!!!!!!!!!!!, a million times NO !!!! and MARYLAND WAS a SLAVE STATE that stayed in the union
*June 11, 2014*

**physics**

Do the vertical problem first Vi = initial speed up then v = Vi - g t at top, v = 0 0 = Vi - g t Vi = g t t = Vi/g h = 0 + Vi t - .5 g t^2 14 = Vi^2/g - .5 Vi^2/g 28 g = Vi^2 Vi = sqrt (28 g) Vi = 16.6 m/s Vi = v sin theta 16.6 = 24 sin theta so ....
*June 11, 2014*

**Physics**

yes (1/2) m v^2 = m g h so h = (1/2) v^2/g
*June 11, 2014*

**math (check answer plz)**

permutations of 8 taken in groups of 3 = 8!/(8-3)! = 8!/5! = 8*7*6 = 336 yes
*June 11, 2014*

**algebra**

n * 1.35 = 1600 + .41 n + 3700 .94 n = 5300
*June 11, 2014*

**math *check* (PERMUTATION)**

3 * 2 * 1 = 6
*June 11, 2014*

**physics**

72/3.6 = 20 meters/second (helpful to remember 1000 meters /3600 seconds = 1/3.6) 0 = 20 + a t t = -20/a x = Xi + Vi t + (1/2) a t^2 200 = 0 + 20 t + .5 a t^2 200 = 0 -400/a + .5 a (400/a^2) 200 a = -400 + 200 a = -1 so d, retardation of 1 m/s^2 ------------------------ ...
*June 11, 2014*

**physics**

d/2 = 30 t1 so t1 = d/60 d/2 = 50 t2 so t2 = d/100 t = t1 + t2 d = v (t1+t2) = v (d/60 + d/100) 100 = v ( 5/3 + 3/3) = (8/3) v v = 300/8 = 37.5 km/hr
*June 11, 2014*

**physics**

0 = 14.1 - 3.2 t as Janet told you below.
*June 11, 2014*

**Math**

probability of what? one one and the ten or two ones or what? I guess I will assume you mean what is the probability of getting ten plus one first draw, probability of ten = 1/5 if you missed, you now have three ones and a ten probability of ten = 1/4 so the total probability ...
*June 10, 2014*

**math**

http://www.jiskha.com/display.cgi?id=1402442232
*June 10, 2014*

**math**

I just did that
*June 10, 2014*

**Macroeconomic**

I doubt it.
*June 10, 2014*

**math (check answer plz)**

37 marbles? first draw (red) 6/37 second time (independent because you replaced the marble and still have 37 blue 8/37 so 6/37 * 8/37 = 48/1369 You multiply to get probability of two independent events both happening, you add if two things satisfy your condition such as if ...
*June 10, 2014*

**Math- urgent**

You do not. Those are functions of an ANGLE, not a triangle They are defined in a right triangle. If A is one of the two angles that is not 90 degrees then sin A = opposite side/hypotenuse cos A = adjacent side / hypotenuse tan A = sin A/cos A = opposite/adjacent
*June 10, 2014*

**math (please check answer)**

You are welcome.
*June 10, 2014*

**math (please check answer)**

probability of failure = 147/156 it has to be one or the other so 1 - 147/156 = 9/156 = 3/52 agree
*June 10, 2014*

**math**

a ar ar^2 ar^3 sum of first 4 = a (1-r^4)/(1-r) = 32.5 a r^3 = 3375 a r^3 = 3375 r = 15 a ( 1-r^2)(1+r^2) /(1-r) = 32.5 a (1+r)(1+r^2) = 32.5 a (16)(226) = 32.5 a = .0089878 about 1 cent :) ar = .1348 ar^2 =2.02 ar^3 = 30.33 about 30 dollars
*June 10, 2014*

**math**

alcohol removed = 1/10 liter first time = 1/10 (.9) liter second time = 1/10 (.9)(.9) third time .... =1/10 (.9)^6 seventh time so amount removed = .1 + .1*.9^1 +....1*.9^6 seven terms a = .1 sum removed = .1 (1-.9^7)/.1 = .478 so amount remaining = 1-.478 = .522
*June 10, 2014*

**Physics**

You are welcome.
*June 10, 2014*

**Physics**

110 km/hr = 110,000 m/3600 s = 30.6 m/s m g h = (1/2) m v^2 9.81 h = .5 (30.6)^2 h = 47.7 meters (b) loss of energy = m g (47.7-22) = 750(9.81)(25.7) = 189,000 Joules lost (c) work done = force in direction of motion * distance moved 189,000 = F (22/sin2.5) F = 375 N
*June 10, 2014*

**Math**

distance = speed * time 3.54 * 10^7 = 3*10^8 t t = 3.54/3 * 10^-1 t = 3.54 / 30 = 0.118 seconds
*June 10, 2014*

**math**

dp/dt = p/8 dp/p = .125 dt ln p = .125 t + c p = Po e^.125 t
*June 10, 2014*

**math**

1.08^10 = 2.16 2.16 * 10,000 = 21,589.25
*June 10, 2014*

**math**

a ar ar^2 ar^2 - a = 25 or a (r^2-1) = 25 ar^2 - ar = 15 or ar(r-1) = 15 [25/(r^2-1) ] r (r-1) = 15 r (r-1) /[ (r+1)(r-1) ] = 15/25 = 3/5 r/(r+1) = 3/5 5 r = 3 r + 3 2 r = 3 r = 3/2 = 1.5 then a r^2 - a = 25 1.25 a = 25 a = 20 so 20, 30, 45, .....
*June 10, 2014*

**Math**

You are welcome.
*June 10, 2014*

**Math**

2 = e^35 k ln 2 = 35 k k = .0198 so a = 1400 e^.0198*3*60 a = 1400 e^3.565 a = 49,475.2
*June 10, 2014*

**Physics**

area of loop = .02^2 = .0004 m^2 dB/dt = .044/.1 = .44 emf = A dB/dt = .0004 *.44 = 1.76 * 10^-4 = .00018 V
*June 10, 2014*

**Physics**

Seems to me they better repel each other so I agree with you.
*June 10, 2014*

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