Tuesday

July 22, 2014

July 22, 2014

Total # Posts: 17,481

**Calculus**

http://www.wolframalpha.com/widget/widgetPopup.jsp?p=v&id=7c9206fea2b96c1f22626b03b18327b3&title=Math+Help+Boards:+Indefinite+Integral+Calculator&theme=blue says: (x-1)/[7 sqrt(x^2-2x+8) ]

**Calculus**

∫(x2 − 2x + 8)^-1.5 dx

**Calculus - not sure how but rewrote**

I do not know but suspect you mean ∫1/(x^2 − 2x + 8)^(3/2) dx

**physics**

101.5 * 10*3 + 1029 *9.81 * 9.5 = 101.5 * 10^3 + 95.898 * 10^3 = 197 k Pa or about 2 atmospheres note, 30 feet deep is about additional atmosphere

**physics**

x = A sin wt v = A w cos wt a = -A w^2 sin wt = -w^2 x F = m a so -kx = - m w^2 x w^2 = k/m w^2 = k/.0029 w = 18.6 sqrt k when w t = 2 pi, t = T = 5.5 so (18.6 sqrt k) (5.5) = 2 pi sqrt k = .0615 k = .0038

**physics**

x = .084 sin wt max x = .084 when sin w t = 1 then Pe = (1/2) k x^2 = (1/2) 204)(.084)^2 now what is Ke when sin wt = 1? v = .084 w cos wt if sin wt = 1, then cos wt = 0 because sin^2 + cos^2 = 1 always so v = 0 when sin wt = 1 so TOTAL energy = PE at sin wt = 1 = (1/2) (204)(...

**physics**

x = a sin wt v = a w cos wt a = -a w^2 sin wt = -w^2 x F = m a = -kx when x = 0, equilibrium , sin wt = 0 and cos wt is 1. That is max velocity when w t = pi/2, cos wt = 0 so v = 0 v = a w cos wt which is certainly not constant a = -a w^2 sin wt = -w^2 x which is 0 when x = 0 ...

**physics**

from t = 0 to t = .02 she goes(.21 - .043) = .167 .167 m / .02 seconds = 8.35 m/s

**english**

multiple sclerosis Is the correct spelling I think.

**PHYSICS**

calculate distance 20*2 + 40*2 + 60*6 = calculate time 2+2+6 av speed = distance/time

**Biomechanics**

You exceeded he elastic limit of the material and permanent bending occurred.

**Algebra**

5*4 the rest cancels.

**Algebra**

(x-3)(x+5) well, if x were 4 It could be 9 x 1 or if x were 5 it could be 10 x 2 or if x were 6 it could be 11 x 3 or if x were 7 it could be 12 x 4 etc

**Science**

This question would take all night to answer. I will just make a suggestion or two. Just think about sources. Obviously burning carbon causes CO2 no matter what form the carbon takes (coal, diesel, gasoline, methane ..... ) Some create more problems than others, coal for examp...

**Damon, Still need your help please tho**

You are welcome :)

**Damon, Still need your help please tho**

y = k/x 4 = k/6 k = 24 so y = 24/x Just do what it says :)

**Damon, Still need your help please tho**

LOL, many years ago.

**Damon, Still need your help please tho**

I guess C which is 7; where x =/ 2 assuming that x=/2 means not when x = 2

**Damon, Still need your help please tho**

7 where x not equal to 2 (x=2 is not in the domain, function undefined there)

**Damon, Still need your help please tho**

7(x-2) /(x-2) = 7 * 1 = 7 but x may not be 2 or the original denominator would be zero

**Damon, Still need your help please tho**

did the first one already http://www.jiskha.com/display.cgi?id=1402703533#1402703533.1402705078

**Algebra ll**

You are welcome.

**Algebra ll**

x = 3, y = 12 Step 2: Enter the values for your matrix, and press the "Solve" button. Divide row1 by 4 1 -1/2 -3 3 -1 -3 Add (-3 * row1) to row2 1 -1/2 -3 0 1/2 6 Divide row2 by 1/2 1 -1/2 -3 0 1 12 Add (1/2 * row2) to row1 1 0 3 0 1 12

**Algebra ll**

+4 -2 -12 +3 -1 -3 gauss jordan see http://www.gregthatcher.com/Mathematics/GaussJordan.aspx

**Tricky Math tho (Damon)**

Yes, C

**Tricky Math tho (Damon)**

OH !! remainder allowed just do long division 5x - 5 with remainder of 3 so 5x - 5 and 3/(5x-3)

**Tricky Math tho (Damon)**

try factoring the top. If this problem is possible, a factor is (5x-3) (5x-3)( 5x +or-6 to get 18) (5x-3)(5x-6) hey are you sure it was not 25 x^2 -45 x + 18 ?????

**Almost done with this math tho**

It is 7 but there is no solution if x = 2 (undefined, zero denominator, not in domain)

**Almost done with this math tho**

7(x-2) / (x-2) = ?

**Algebra**

do you mean 1/x + 1/(x+5) + 1/(3x) = 100/225 ???? 225/x +225/(x+5) + 75/(x) = 100 300/x + 225/(x+5) = 100 (x+5)(300) + 225 x = 100x(x+5) 300 x + 1500 + 225 x = 100 x^2 + 500 x 100 x^2 -25 x -1500 = 0 20 x^2 - 5 x - 300 = 0 4 x^2 - x - 60 = 0 (x-4)(x+15) = x = 4 or x = -3.75

**this math tho (Damon or Steve)**

30 = 5 * 2 * 3 all prime numbers so sqrt (30) is sqrt (30) period however sqrt on the bottom is no fun, should rationalize multiply top and bottom by sqrt 30 (5/sqrt30)(sqrt30/sqrt30) = (5 sqrt 30) /30 = sqrt (30) /6

**this math tho**

You are welcome :) No thinking, just doing and CHECKING

**this math tho**

x^2 - 6 x + (6/2)^2 = 7 + (6/2)^2 x^2 - 6 x + 9 = 7 + 9 (x-3)^2 = 16 (x-3) = 4 or (x-3) = -4 x = 7 or x = -1 check 1 + 6 = 7 49 - 42 = 7

**Another this math tho**

2 * 1 = 2 b^-6 * b^12 = b^(-6+12) = b^6 so yes, 2 b^6

**this math tho**

well, first of all, check your answer back in the originl for example if x = 8 3 (8-4) + 54 = -3(8) ???? 12 + 54 = -24 I doubt it Now let me try 3 x - 12 + 54 = -3 x 6 x + 42 = 0 x = -42/6 = -7 now check that back in the original

**ALGERBRA**

that comes out to: .0004952 or use combinations 13 hearts in deck number of combinations of 5 in 13 = c(13,5) = 13!/[ 5!(8!) ] = 1,287 5 in 52 = 52!/[5!(47!)] = 2,598,960 quotient = .0004952

**ALGERBRA**

first card 1/4 second card 12/51 third card 11/50 fourth card 10/49 fifth card 9/48 multiply :)

**math**

You are welco0me. Just remember to reverse arrow when multiplying (or dividing) by negative quantity

**math**

14 < -2x 7 < -x or -7 > x reverse arrow when multiplying by negative quantity or x <-7 check that, for example if x = -8 14 + 7x = 14 - 56 = -42 5 x = -40 so yes, 14 + 7x < 5x

**Financial Math**

2500 * (1.03^6) = 2985.13 now 2985.13 (1+ .05/12)^24 = 3298.39 3298.39 -2500 = 798.39

**English**

5 is the only one that sounds right to me.

**algebra**

look at that second equation. You can easily solve it for y namely y = 2x-1 so use (2x-1) for y in the first equation 3 x - 4(2x-1) = 5 3 x - 8 x + 4 = 5 -5 x = 1 x = -1/5 then y = -2/5 -1 = -7/5 check that -3/5 +28/5 = 25/5 = 5 yes, checks -2/5 + 7/5 = 5/5 = 1, yes, so we hav...

**algebra**

x = 3 , y = 2 is the intersection

**algebra**

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

**algebra**

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

**Math**

You are welcome.

**Math**

anything to the 0 power is 1 anything divided by itself is one unless the denominator is zero.

**typo**

plus or minus 60 x

**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.

**algebrahave i done this right**

You are welcome :)

**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

**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

**typo?**

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

**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

**Algebra please can you ck my work**

check my earlier answers things are getting worse except for the 152 ---512 typo

**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

**PHYSICS**

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

**Algebra**

You are welcome.

**Algebra**

40/1.6 = n/5 so n = 200/1.6 = b) 150 * 1.6/40 =

**USA Colonists History**

http://www.mainememory.net/sitebuilder/site/283/page/546/display

**USA Colonists History**

... or fresh water :)

**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.

**USA Colonists History**

catch cod, sell it in the West Indies and Europe catch beavers, sell fur in Europe

**Physics**

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

**Physics**

yes, up means higher frequency

**Physics**

yes

**algebra**

1 and 2 that is 2/6 or 1/3 450/3 = 150

**Physics**

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

**Physics**

You are welcome.

**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.

**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

**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

**PHYSICS**

2 pi radians every 60 seconds 2 pi/60 = pi/30

**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

**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

**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

**Math**

pi d^2/4 h (3.14 * 7.4*7.4 * 2.4 ) / 4

**MATH**

integral of e^(Lx)dx = (1/L) e^(Lx) + c

**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 c...

**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)

**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

**physics**

F = k x 10.5 = k (.72 k = 10.5 N/.72 m

**Science(electric circuits)**

Maybe the total current is the sum of the currents through the individual paths.

**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

**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

**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

**Science(electric circuits)**

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

**physics**

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

**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

**physics**

http://www.jiskha.com/display.cgi?id=1402590278

**Science(electric circuits)**

voltages across individual elementsd add in a series circuit.

**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.

**Science(electric circuits)**

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

**science (help)**

water, fresh and salt.

**Algebra**

clark + clark + 5 = 33 2 clarks = 28 clark = 14 so shelly = 19

**Math**

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

**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

**Physics**

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

**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

**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

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