Thursday

April 17, 2014

April 17, 2014

Total # Posts: 16,150

**math**

Now I did the bottles one, you do this one.

**math**

cost per bottle = c price per bottle = p 16 p = 17 c p = 1.0625 c gain = .0625 c = 6.25 %

**logic**

sunday + 7 n = sundaay 100/7 = 14.2857 = 14 + 2/7 so sunday + 14 weeks + 2 days = Tuesday :)

**Math**

perimeter = twice length + twice width L = length = 1 b = .55 meter 2 * 1 + b = 2 L + 2 w so b = 2 w and w = .55/2 = .275 area = L w = 1 * .275 = .275 m^2 perimeter = 2*1 + 2*.275 = 2+.55 = 2.55 m

**logic**

I made a 4 by 4 grid and filled it in ---> ____A ____ B_________C________D --A-- ____* _____B1A1 _____C1A1 ___D0A2 --B ---- A1B1_____ * ______C0B2 ___D1B1 --C ---- A1C1____ B2C0______ * ____D0C2 --D ---- A2D0 ____B1D1 ____C2D0_____*

**math**

160.65 /x = 99.45/13 x = 13 * 160.65/99.45 = 21 hours worked if constant pay per hour

**U.S History - Pls check my answer, tks :)**

Remember the fate of the Choctaw, Cherokee, and Creek was to be shipped off on the notorious "trail of tears" (Google that) by this same now bleeding heart President Jackson. It looks to me like he is devising an excuse to uproot them despite their often successful a...

**Story problem heellp**

been there, done that scroll down

**GEOMETRY CIRCLES EQUATION**

been there, did that http://www.jiskha.com/display.cgi?id=1392638255

**Story problem**

2 L + 2 w = 104 so L + w = 52 and L = (52-w) L + 8 = 2 w 52 - w + 8 = 2 w w = 30 L = 52 - 30 = 22

**Story problem**

a + b = 90 a - b = 18 ----------- add 2 a = 108 a = 54 b = 90 - 54 = 36

**geometry circles equation i dont know**

points on circle: (0,0), (5,0) find intersections of lines for third point on circle 2(y) + 3 y = 10 5 y = 10 y = 2 then x = 2 so third point is (2,2) (0,0) (5,0) (2,2) (x-a)^2 + (y-b)^2 = r^2 plug and chug a^2 + b^2 = r^2 (5-a)^2 + b^2 = r^2 (2-a)^2 +(2-b)^2 = r^2 a^2 + b^2 =...

**Physics**

pull force = 125 cos 40 lift force = 125 sin 40 Fdown on floor= 55*9.81 - 125 sin 40 friction force back = Fdown*mu F = m a = 0 so 125 cos 40 = Fdown * mu

**Physical Science**

If any valves were open, you could not compress the gas. 5 KG * specific heat of coal * 200 coal around 1.3 *10^3 J/kgK 5 * 1.3 *10^3 * 200 = 1,300,000 so a.

**Physics**

google "Einstein, photoelectric effect"

**Physics**

vertical problem: 0 = h + 0 -4.9 t^2 0 = h - 4.9(.38)^2 h = .708 meters high u = 1.30 forever d = u t = 1.3 * .38 = .494 meters away HORIZONTAL VELOCITY DOES NOT CHANGE !!! (there is no horizontal force.) Hey, you know this. You are making me do things you can do yourself.

**Physics**

F = m a F = charge on electron * E F = 1.6*10^-19 * 1.16*10^4 = 1.856*10^-15 N m = mass of electron a = F/m which is constant a = 1.856 * 10^-15/9.1*10^-34 = .204 * 10^19 m/s^2 V = Vi - a t solve for t, when it stops 0 = 2.35*10^7 - .204 *10^19 t t = 11.52 * 10^-12 seconds I d...

**Physics**

hi = 14 h = 22/2 = 11 u = 40m/2s = 20 m/s 11 = 14 + Vi (2) - 4.9 (4) 2 Vi = -3 + 19.6 Vi = 8.3 m/s tan theta = Vi/u = 8.3/20 so theta = 22.5 degrees Now you should be able to part b

**physics**

E = V/d = 100/.02

**physics**

P V = n R T here V, n and R are constant so P1/T1 = P2/T2 Pi = 325 k Pa T1 = 10 + 273 = 283 T1 = 50 + 273 - 323 P2 = P1 T2/T1

**stats teacher needed**

Your title gives no hint as to if you need an English or Latin teacher or whatever, wasting everyone's time.

**Physics**

well for part a we only need to do the vertical problem Vi = 1690*sin55.7 = 1396 m/s straight up v = Vi - 9.8 t v = 0 at top 9.8 t = 1396 at top t = 142 seconds upward so 2*142.5 in air t in air = 285 seconds = 4.75 min PART A u = horizontal speed forever = 1690cos 55.7 = 952 ...

**maths**

t1 r t1 = t1-4 r^2 t1 = (t1-4) -9 = t1 - 13 r (t1-4) = t1-13 r = (t1-13)/(t1-4) = (t1-4)/t1 so t1^2 - 13 t1 = t1^2 -8 t1 + 16 -5 t1 = 16 t1 = -16/5 = -3.2 then r = (t1-4)/t1 = (-16/5 - 20/5)/-16/5 = 36/16 = 9/4 t2 = -16/5*9/4 = -7.2 = of course t3 = -7.2*9/4 = -16.2 indeed -7....

**Astronomy**

because it is lit up on the SW horizon around sunset

**not enough information given**

I can not understand what the problem is.

**7grade math**

I am a physicist and tend to use unit conversions where an algebra person would use proportions.

**7grade math**

or if you like proportions .75 inch/25 miles = 6.75 inch/x miles x (.75 inch) = = 6.75 inch * 25 miles x = 6.75 * 25 / .75 = 225 miles

**7grade math**

Always do unit problems so the units you do not want cancel and you are left with what you want in this case cancel inches so you end up with miles 6.75 inches ( 25 miles/ .75 inch) = 225 miles

**7grade math**

Huh? 3/4 inch = 25 miles 1 inch = 25(4/3) = 100/3 miles = 33.3333 miles 6 inches = 33,3333* 6 = 200 miles 3/4 inch = 25 miles so 6 inches + 3/4 inch = 225 miles

**7grade math**

6.75 inches ( 25 miles/ .75 inch) = 225 miles

**7grade math**

I did it in the first line above: 6.75 (25/.75) = 225 miles

**7grade math**

6.75 (25/.75) = 225 miles You could have guessed which answer was right by doing 8 * 25 = 200 in your head. It is clearly not going to be less than 30 miles :)

**physics**

.92 * 97 = 89.24 97* 1000/3600 = 26.94 m/s 89.24 *1000/3600 = 24.79 m/s a = change in velocity/change in time how long to reach plate Vaverage = (26.94+24.79)/2 = 25.87 m/s so time to plate = 13/25.87 = .503 s so a = (24.79-26.94)/.503 = 4.27m/s^2 F = m a = .29(4.27) =1.24 N

**Intermediate Algebra**

Look at any of those examples down below. for example: http://www.jiskha.com/display.cgi?id=1294619397

**Math**

3 a + p = 10 o 6 o + a = p write as 3 a + 18 o = 3 p so now 3 a + p = 10 o 3 a + 18 o = 3 p ------------------subtract p - 18 o = 10 o - 3 p 4 p = 8 0 1 p = 2 o so two oranges balance a pineapple

**physical science**

F = m g = G M m/R^2 10 * R ---> 1/100 90 * m ----> 90 9.81 * 90/100 = 8.83 m/s^2

**physics**

NO WORK IS DONE TO MOVE HORizontaly !!!!!! there is no horizontal forCE !!! Do not be fooled !!! m g h = 1 * 9.81 * .51 = 5.00 Joules

**Math**

yes, 80

**Calculus**

now the hard way is v = Vi + a t 0 = 72 + a t a = -72/t x = Vi t + .5 a t^2 1/9 = 72 t + .5 (-72/t) (t^2) 1/9 = 72 t - .5(72 t) or like we said before 1/9 = (72/2) t

**Calculus**

LOL there is a hard way and an easy way the easy way is to know that during constant acceleration the average speed is the average of the beginning and end speeds average speed = 72/2 = 36 mph speed * time = distance 36 * time = 1/9 time = 1 hour/(9*36) 1 hour = 3600 seconds s...

**Math**

16 = 2*2*2*2 20 = 2*2*5 we need 4 twos and a five 16*5 = 80

**Math**

12 = 2*2*3 15 = 3 * 5 so we need two 2s a 3 and a 5 2*2*3*5 = 60

**Math**

smallest (or least I suppose :) usually it is called the least common multiple, or used to be.

**Calculus**

height of rectangle = z width of rectangle = b = base of triangle height of triangle = h length of side of triangle = sqrt[h^2+(.5b)^2] perimeter = p = 2 z + b + 2sqrt(h^2 +.25b^2) area = A = z b + (b/2) h = 200 yuuck

**Ficonacci puzzles**

1 1 2 3 5 8 13 21 34 ... take 2 3 5 -->10 , 9 take 3 5 8 ---> 24 , 25 take 5 8 13 ---> 65 , 64 take 8 13 21 --> 168 , 169 see a pattern ?

**Physical science**

Well, 0 Newtons gives 0 frictional force

**calc**

9 dy/dx = x^2 y^2 9 dy/y^2 = x^2 dx -9 / y = (1/3) x^3 + c when x = 3, y = 1 -9/1 = (1/3)(27) + c -9 = 9 + c c = -18 so -9/y = (1/3) x^3 + c if x = 3 * 3^(1/3) = 3^(4/3) then x^3 = 3^4 so -9/y = (1/3)* 3 * 3^3 - 18 -9/y = 27 - 18 = 9 -1/y = 1 y = -1

**Maths**

(1/9) sqrt 3 * sqrt 27 ? note 27 = 3^3 so sqrt 27 = 3^1.5 3^-2 * 3^.5 * 3^(1.5) = 3^-2 * 3^+2 = 3^0 = 1

**pre-calculas**

well, this one is different anyway -2 x^2 + 6 x + 5 = y find zeros x^2 - 3 y - 2.5 - -y/2 x^2 - 3 y = -y/2 + 5/2 x^2 -3 y + 9/4 = -2 y/4 + 10 y/4 + 9/4 (x- 3/2)^2 = -1/2 (y -19/2) when y = 0 (x-3/2)^2 = 19/4 so x = 3/2 +/- 1/2 sqrt 19 check with quad eqn x = [ -6 +/- sqrt (36 ...

**pre-calculas**

-(x+3)/(x-3)+(12x+4)/(x-3)(x+3) -2x/(x+3) LCD = (x+3)(x-3) which is (x^2-9) so -(x+3)(x+3)/LCD +(12x+4)/LCD- 2x(x-3)/LCD -x^2 - 6x - 9 + 12x + 4 -2x^2 + 6 x all over LCD (-3 x^2 + 12 x -5)/(x^2-9) check my arithmetic

**MORTGAGE**

128,000 * .8 = 102,400 principal p pmt = p [r/{ 1 -(1+r)^-n} ] n = 30 * 12 = 360 r = .085/12 = .00708333 1 + r = 1.00708333 (1 + r)^-360 = .07878669 1 - (1+r)^-360 = .9212133 .08 / .9212133 = .007689 times principal = $787.37

**pre-calculas**

multiply top and bottom by (x-5)(x+5) which is (x^2-25) x^2 - 9 x - 10 = (x-10)(x+1) by the way

**physics**

F = .0566 N still m = .733 a = F/m = .0772 1.44 = .5 (.0772) t^2 t = 6.11 s

**Physics**

We need to know its mass. Rearth = 6.380*10^6 meters Rorbit = 12.380*10^6 meters gain in potential energy + kinetic energy Potential: +G M m/rearth - G M m/rorbit = gain in potential energy Kinetic G M m/rorbit^2 = m V^2/rorbit V^2 = G M/rorbit Ke = (1/2) m V^2 add potential a...

**math**

LCD is 48 tuesday 14/48 wed 11/48 thurs 9/48 fri 6/48 total so far = 40/48 a) (9/48)100 = 18.75 % b) 48/48 - 40/48 = 8/48 = 1/6 c) (7/24)900 = 262.5 km

**Probability**

http://www.jiskha.com/display.cgi?id=1392506096

**Probability**

That is the way I listed them in my reply to you, but the column you use for each does not matter. In other words it does not matter what order you toss them, just toss each of them once. I headed the first column p the second n the third d

**Physics**

speed north = 30 - 130 sin 30 = -35 speed west = 130 cos 30 = 113 tan angle south of west = 35/113 so angle south of west = 17.2 deg so 270 - 17.2 = 253 on the compass rose

**Physics**

sine of slope angle = .195/1.36 = .143 angle = 8.24 degrees cos slope angle = .99 weight = 1.1 * 9.81 = 10.8 N component of weight down slope=10.8(.143) = 1.54 N a = F/m = 1.54 / 1.1 = 1.40 m/s^2 d = (1/2) a t^2 1.36 = (1/2)(1.40) t^2 t = 1.39 seconds

**Calculus**

dy/dx = slope = 1 - x/250 y = m x + 20 at tangent point y = (1-x/250) x + 20 = x - x^2/500 solve that for x

**Physics Help**

You forgot the weight weight = m g = 5(9.81) = 49 N so 100 N up, 49 down net force = 51 N up a = F/m 51/5 = 10.2 m/s^2

**Math help**

2 a - 1 b = 1 2 a + 6 b = 8 (multiplied eqn 2 by 2) -------------- subtract -7 b = -7 b = 1 then a = 1 ================================= -1 x + 1 y = 2 +2 x + 1 y = 8 ------------------subtract -3 x = -6 x = 2 then y = 4

**Math: Probablity**

p n d H H H H H T H T H H T T T H H T H T T T H T T T C two heads ---> 3 d P(HHT) = 1/8 e 3/8 f 4/8 = 1/2 g 2/8 = 1/4 h 6/8 = 3/4 i 1/8 j 1 k zero, not in set

**RE: Physics**

Sorry, sin not cos opposite / hypotenuse = sin 8.60 degrees

**physical**

m (4 m/s) = 600 kg m/s m = 150 kg

**physical**

original momentum in x direction = .4*3 - .8*2 = 1.2 -1.6 = -0.4 kg m/s so moves to left if first car was moving right final momentum in x direction = (1.2)v final momentum = original momentum (first law) 1.2 v = -0.4 v = - 1/3 meter/second

**Differential Equations**

(2y -x) dy = y dx 2 y dy - x dy = y dx 2 y dy = x dy + y dx y^2 = x y + c when x = 0 y^2 = c = 1 y^2 = x y + 1

**Physics**

cos (angle) = .178/1.19

**college math**

6 x^3 + 27 x^2 - 15 x ?? It is a cubic polynomial with one root at x = 0 and use the quadratic equation to find the other two.

**Astronomy**

because it is just barely above the horizon in the direction of the sun just as the sun set. See the reference I just gave you: http://www.cfa.harvard.edu/pao/skyreport/solar_system.html

**Astronmy**

Just about between us and the sun see http://www.cfa.harvard.edu/pao/skyreport/solar_system.html

**Differential Equations, Matrices**

cos45 -sin45 sin45 cos45 is 1/sqrt2 -1/sqrt 2 1/sqrt 2 1/sqrt 2 x' = x/sqrt2 - y/sqrt2 y' = x/sqrt2 + y/sqrt2 so x/sqrt2 + y/sqrt2 =3(x^2/2-2xy/2+y^2/2) +2 original vertex at (0,2) x' = 0 - 2/sqrt2 y' = 0 + 2/sqrt2 so (-sqrt 2 , sqrt 2) for (-1,5) x' = -1/s...

**Physics**

a = change in velocity/time a = (12-0)/ (177* 10^-3) = 67.8 m/s^2 distance = average velocity * time = 6 * 177*10^-3 = 1.06 meters F = m a m = 2.28/9.81 = .232 kg F = .232 * 67.8 = 15.7 horizontal force there is also a vertical force up by the pitcher = 2.28 to keep it horizon...

**physics**

v = omega R omega = (44.5 m/s) / (.385 m)

**perimeter**

outside dimensions = 28 by (x+8) garden dimensions = 20 by x concrete area = 28(x+8) - 20 x = 8 x + 224 cost = 88 (8 x + 224) = 704 x + 19712

**Advanced Maths**

QB = flow rate through big pipe QB = 1 res /t hours QS = flow rate through small pipe QS = 1 res / (t+3) hours 2 (QB+QS) = 1 res 2 [ 1/t + 1/(t+3) ] = 1 2(t+3) + 2 (t) = t^2 + 3 t 2 t + 6 + 2 t = t^2 + 3 t t^2 - t -6 = 0 (t-3)(t+2) = 0 t = 3

**Intermediate Algebra**

http://www.mathsisfun.com/data/grapher-equation.html

**Intermediate Algebra**

http://www.mathsisfun.com/data/grapher-equation.html

**Physics Total Mechanical Energy**

If it is at rest 50 m high, the total is m g h = 575 * 9.81 * 50 = 282,037 Joules The speed does not matter because we counted the total while at rest. However let's see ho much kinetic energy it has at the bottom (1/2) m v^2 = .5*575*31.3^2 = 281,660 Joules so to 3 signif...

**Math help polynomial**

Do operations inside parentheses first.

**Math help polynomial**

-3x(3 y^2) = -9 x y^2

**math**

http://www.jiskha.com/display.cgi?id=1392477199#1392477199.1392477396

**math**

no digit here is ten times another however 7,000 = 10 (700) and perhaps that is what the question means.

**physical science**

been there, scroll down

**physical science**

Vi up = 10 sin 60 = 8.66 m/s if ax is horizontal acceleration, there is none. Horizontal component of velocity is constant

**Math**

2^(x-1) = 3^(1-x) ????? (x-1) log 2 = (1-x) log 3 x log 2 - log 2 = log 3 - x log 3 x (log 2 + log 3) = log 3 - log 2 x = (log 3 - log 2)/(log 3 + log 2) you could look those up

**Math**

4 log x = log x * log x * log x log x * log x = 4 log x = 2 x = 10^2 = 100 if base 10 logs

**PHYICS**

Ac = v^2/R new Ac = (3 v)^2/R = 9 v^2/R 9 times :)

**physical sciences**

http://www.jiskha.com/display.cgi?id=1392457436

**PHYICS**

average angular velocity during stop = 45/2 = 22.5 rad/sec so total angle = 22.5 rad/s * 5 s = 112.5 radians 112.5 radians / 2 pi radians/revolution = 17.9 revolutions

**Physics**

m g h = increase of potential energy 80 * 9.81 * 10^3 = 785*10^3 Joules 785*10^3 = (1/4) total fuel energy burned so total fuel burned = 3.14 * 10^6 Joules 3.14 * 10^6 J / 37*10^6 J/kg = .085 kg

**Calculus 3**

I got sqrt 5 on the bottom

**Algebra**

10 log (2.4*10^-5/10^-16) 10 [ log 2.4 + log 10^11] 10 [11+.38] = 114

**Chemistry**

1 atm = 10.1 Newtons/cm^2 to find that type 1 atm = Newtons/cm^2 into a Google search box 10.1 Newtons/cm^2 * 17.5*10^3 cm^2 = 177,000 Newtons use the Google search box again: 177000 newtons = pounds and you will get back 39,791 pounds

**Simplify 2**

You are welcome :)

**Simplify 2**

19^.5 * 19^.5 = 19^(.5+.5) = 10^1 = 19

**Intermediate Algebra**

here is the method. Put your numbers in: http://www.jiskha.com/display.cgi?id=1294619397

**Physics**

u = 16.1 cos 44 = horizontal velocity the whole time Vi = 16.1 sin 44 = initial vertical velocity h = Hi + Vi t - 4.9 t^2 3 = 0 + Vi t - 4.9 t^2 4.9 t^2 - (16.1 sin 44) t + 3 = 0 solve quadratic for t, use the big one v = Vi - 9.8 t u = 16.1 cos 44 still speed^2 = u^2 + v^2

**Geometric Constructions HELP!**

well, wings are symmetrical port and starboard but not identical replacement cartridges for your printer. DVDs most replacement machinery parts for example new nut for bolt.

**Math**

f-g = -3 x +irrelevant - 9 x - irrelevant = -12 x + b slope = m = -12 Now you knew these last two perfectly well. Give your answer and let us just check.

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