Thursday
November 27, 2014

Posts by Damon


Total # Posts: 19,590

math
9 + 63 = 72 using rounding which happens to be exact and I also call 9 and 63 compatible numbers since adding 9 to anything is super easy.
August 18, 2014

physics
V defined as speed out of the barrel time rising = time falling so find rise time and multiply by 2 vertical problem: Vi = V sin 30 = .5 V v = Vi - 9.8 t v = 0 at top 0 = .5 V - 9.8 t so t = .5 V/9.8 and 2 t = total time aloft = V/9.8 at max height there is no vertical ...
August 18, 2014

physics
You are welcome :)
August 18, 2014

physics
if none were added dN/dt = k N number produced per second = 10 number lost per second = k n so dN/dt = 10 - k N N is maximum when dN/dt = 0 0 = 10 - k (1000) k = .01 so we know that for this fission reaction (without the inflow) dN/dt = -.01 N dN/N = -.01 dt ln N = -.01 t + C ...
August 18, 2014

probability
first red = 8/24 second blue = 4/23 so (1/3)(4/23) = 4/69
August 17, 2014

Engineering maths
outside dimensions of deck are L and W inside dimensions of deck are 30 and 22 so Area of deck = L W - 660 so L W - 660 = 480 L W = 1140 if x = deck width Length L = 30 + 2x W = 22+2x so (22+2x)(30+2x) = 1140 multiply out and solve quadratic
August 17, 2014

physics
I think they mean total acceleration up
August 17, 2014

physics
Vi = a t = 32 * 4.1 = 131 m/s at burn out h = (1/2)32 (4.1)^2 = 269 meters at burn out then v = Vi + a t at top v = 0 0 = 131 - 9.8 t t = 13.4 seconds coasting up h = 269 + 131 (13.4) -4.9 (13.4)^2
August 17, 2014

computers
Yes, http://www-03.ibm.com/ibm/history/exhibits/pc25/pc25_birth.html
August 17, 2014

computers
As I remember Microsoft
August 17, 2014

important math question
http://archives.math.utk.edu/visual.calculus/3/newton.5/
August 17, 2014

important math question
sorry, x - y / dy/dx
August 17, 2014

important math question
Newton's method for finding zeros f(x) = x^3 -x-5 pick an x in the range, say x = 2 f(2) = 1 f'(2) = 3 x^2 - 1 = 11 mark that point (2,1) and slope of 11 through it now that slope will hit the x axis at x + y / dy/dx or 2 + (-1)/11 = 1.909 now repeat again and again ...
August 17, 2014

important math question
Did you click on the polynomial calc link? You can use Newton's method. I will give you a link in a minute. Oh, no need, this next problem is in fact Newton's method. Draw a sketch f(3) = 5 Put an x at (3,5) slope ay (3,5) = -2 f(x+dx) = f(x) + slope * dx f(3 + .02) = ...
August 17, 2014

typo
1.90416
August 17, 2014

important math question
The only real root is x = 1.0416 http://www.mathportal.org/calculators/polynomials-solvers/polynomial-roots-calculator.php
August 17, 2014

trigonometry
draw a sketch cos 68 = x/43
August 17, 2014

Algebra
Every integer is a rational number because you can divide it by one.
August 17, 2014

Precalculus
at least one typo 2Z-W=(2Zx-Wx)i+(2Zy-Wy)j |2Z-W|^2=4Zx^2-4ZxWx+Wx^2+4Zy-4ZyWy+Wy^2 =4|Z|^2+|W|^2 -4(ZxWx+ZyWy)= 625 and |Z+2W|^2 =|Z|^2+4|W|^2 +4(ZxWx+ZyWy)=25 so 625+25 =5[ |Z|^2+|W|^2| ] or 130 = |Z|^2 + |W|^2 now that last one |Z+W|^2= Zx^2+2ZxWx+Wx^2+Zy^2+2ZyWy+Wy^2] = 4 ...
August 16, 2014

Precalculus
You asked for it: 2Z-W=(2Zx-Wx)i+(2Zy-Wy)j |2Z-W|^2=4Zx^2-4ZxWx+Wx^2+4Zy-4ZyWy+Wy^2 =4|Z|^2+|W|^2 -4(ZxWx+ZyWy)= 625 and |Z+2W|^2 =|Z|^2+4|W|^2 +4(ZxWx+ZyWy)=25 so 625+25 =5[ |Z|^2+|W|2| ] or 130 = |Z|^2 + |W|^2 now that last one |Z+W|^2= Zx^2+2ZxWx+Wx^2+Zy^2+2ZyWy+Wy^2] = 4 ...
August 16, 2014

mathematics
well lets see 14 23 32 41 50 could be 23 or 41
August 16, 2014

Physic - Oh well, Google might help
http://antoine.frostburg.edu/chem/senese/101/measurement/faq/indiana-jones.shtml
August 16, 2014

Physic sorry :(
LOL, can not help with this, did not see movie !
August 16, 2014

Math
ALMOST !!! sign error - dx /[(x+dx+3)(x+3) ] divide by dx -1/[(x+dx+3)(x+3) ] now let dx -->0 -1/(x+3)^2 which any calculus text will tell you is the right answer d/dx (1/u) = [bottom*d top - top d bottom]/bottom squared
August 16, 2014

Math
oh, much more fun !
August 16, 2014

Math
sqrt 2/ 4 = .35355 which is what our table and graph said
August 16, 2014

Math
no it is one quarter of the square root of 2
August 16, 2014

Math
Now that was fun but you do the next one :)
August 16, 2014

Math
sorry 1/ [2 sqrt2) multiply top and bottom by sqrt 2 to rationalize and we get (sqrt 2) / 4 as we knew all along
August 16, 2014

Math
x y 1.0 .318 0.5 .334 0.2 .345 0.1 .349 .05 .351 .02 .353 .01 .353 .001 .35351 etc which looks much like (sqrt 2 )/4 [(x+2)^.5-2^.5]/x * [(x+2)^.5+2^.5] ----------------------------------- [(x+2)^.5+2^.5] [(x+2) -2] = ------------- x [ (x+2)^.5+2^.5] = 1/ [(x+2)^.5+2^.5] which...
August 16, 2014

Math
http://www.wolframalpha.com/input/?i=%28%28x%2B2%29^.5-2^.5%29%2Fx
August 16, 2014

Math
You are welcome.
August 16, 2014

Math
By the way since this particular function is linear, constant slope, there was no need for us to take the limit to find the derivative (slope at x is slope at any x)
August 16, 2014

Math
this is the definition of the derivative f(x+dx) = 3(x+dx)-2 = 3 x + 3 dx -2 f(x) = 3 x - 2 f(x+dx) - f(x) = 3 dx divide by dx = 3
August 16, 2014

fitness
I do not know what to say :(
August 16, 2014

fitness
Having already found differing answers to these questions online, I think you better use the ones in your text book.
August 16, 2014

Algebra
2.5 * 144
August 16, 2014

fitness
Question 3 I suppose they mean the average baby.
August 16, 2014

fitness
Please post answers when you find them :)
August 16, 2014

physical
the deaths from heart, cancer and stroke, but they add to 50% which is not on your list of answers.
August 16, 2014

physical
That same site has the answer to question 2 in a link.
August 16, 2014

geometry
Must be less than 3+5 and more than 5-3
August 16, 2014

geometry
2 2 3 3 3 1
August 16, 2014

Math
by "right" do you mean "right triangle" ? If so then tan B = b/a B = tan^-1 (b/a)
August 16, 2014

calculus
Hey, you are doing great ! These last two were harder than the ones you asked for help with.
August 16, 2014

calculus
good, that is a long one :) add, then multiply, then add
August 16, 2014

calculus
3 min = 180 seconds downstream = 5 * 180 across = 12 * 180 hypotenuse = sqrt (across^2 + downstream^2)
August 16, 2014

calculus
in the x direction 6 * 1 = 6 int the y direction 2 * -4 = -8 in the z direction 0 * 1 = 0 6 + -8 = -2 see: http://www.mathsisfun.com/algebra/vectors-dot-product.html to see how to do it with |A| * |B| * cos theta
August 16, 2014

Physic
hard to say without knowing the volume. duck it in a full cup and measure the amount of water that flows over the lip.
August 16, 2014

Physics 2
Hard to say without knowing the distances... In general F = k Q1 Q2 /|R^2| iin direction of R If horizontal length = a and vertical height = h Q is lower right Q1 is lower left Q2 is upper left Q3 is upper right R is vector from Q to one of the other 3 Rx = x component of R Ry...
August 16, 2014

Algebra
I am not sure your superscript shows up on everyone's screen. 5 (14-20)^2 /2 = 5 * 36 /2 = 5 * 18 = 90
August 16, 2014

physics, mit 2.01x, mechanical engineering
If you tried to copy and paste the drawing or sketch of this truss here, it did not work because copy and paste is not allowed here. From what you said, moment of inertia of the cross section must be increased or length of section reduced assuming you are doing Euler column ...
August 15, 2014

math
how many buggies? 21 = 9 + 3 n n = 4 4*4 = 16 21 - 16 = 5
August 14, 2014

Math
1+2+3 average is (1+3)/2 = 2 2*3 = 6 check :) so I think it is (1+31)/2 = 16 16*31 = 496
August 14, 2014

math
-2 = -1/.5 so they are perpendicular, yes, C
August 14, 2014

math corrections
profit, p = revenue, r - cost, c r = revenue = 25 g c = cost = 75 so p = 25 g - 75 so if p >/= 50 then 25 g - 75 >/= 50 so you are right. It is E.
August 14, 2014

math
4.85/4 = 1.21625 = quarterly percent 11 years = 44 quarters (1.0121625)^44 = 1.7022 3,500 * 1.7022 = 5957.70 so agree. I do not see any list of staetements
August 14, 2014

mathematics
x+6
August 14, 2014

math corrections
I agree with your answer, C and have no idea why it is called incorrect.
August 14, 2014

math corrections
1, 5c 2 10 c 3, 15 c 4, 25c 5 30C 6 35 c 7 40 c 8 50 c 9 55 c 10 60 c 11 65 12 75 c 13 80 c 14 85 c 15 90 c
August 14, 2014

math
4000/7 = 571.4 so we need a little more than 571 572 will do 572 * 7 = 4004, check :)
August 14, 2014

math
5 28 = 300 + 28 = 328 6 43 = 360 + 43 = 403 sum = 731, agree
August 14, 2014

Finance
If your in county prices go up so you must pay more of your coins for a banana, then your coins will buy fewer of my bananas and is worth fewer of my coins which can still buy as many bananas as they did last year.
August 14, 2014

fundinjobo high science
H2 is 2 grams/mol so we have 40 mols of H2 which is 80 mols of H for each mol of H we get 1/3 mol of NH3 so we get 80/3 mols of NH3 NH3 is 14+3 = 17 grams/mol (80/3)mols * 17 grams/mol = 453 grams NH3
August 14, 2014

math
y = 14 t - 4.9 t^2 if you do not know physics or calculus you must complete the square to find the vertex of the parabola. 4.9 t^2 - 14 t = -y t^2 - 2.857 t = -(1/4.9) y t^2 - 2.857 t + 1.429^2 = -(1/4.9)y+2.04 (t-1.429)^2 = -(1/4.9)[ y - 10 ] vertex at height 10 meters and ...
August 14, 2014

history
http://history.howstuffworks.com/revolutionary-war/hartford-convention.htm B. mainly ports for international trade. (Boston, Philadelphia, New York, Charleston, the ports in Va and MD ....... Hey, Google this stuff !
August 14, 2014

history
....... from Albany to ______ Oh well :(
August 14, 2014

math
What are you talking about? 15,000 (1 + 0.10/12)^12n for 6 years 15,000(1.008333)^72 = 15,000*1.8176 = $ 27,263.91 for 12 years 15,000 (1.008333)^144 = $49,554.73 etc
August 14, 2014

math
4 s = 20 s = 5
August 14, 2014

maths probably typo but all right here is your cost
I suspect you men .10 or 1.0 times 8 per mile not $10 per (1/8) mile but since you used 10 I will go along with $80 per mile c = 1.8 + 80 m c(4.5) = 1.8 + 80 (4.5)
August 14, 2014

Maths
.75 fruits = orange or .75 f = oj .25 fruits = apples or .25 f = a oj - 10 = .5 a so .75 f - 10 = .125 f .625 f = 10 f = 16 answer now check 12 + 4 = 16 yes 12 - 10 = 2 2 = half of 4 yes
August 14, 2014

maths parentheses? might as well be Martian
I can not decipher your text right off for example (36/25)^(3/2) or [36/(25)^3]/2 or what, no hope unless you use parentheses properly
August 14, 2014

Math
if y = a x^n then dy/dx = a n x^(n-1) so if y = 2400 x^1 - 2 x^2 then dy/dx = 2400 (1) x^(1-1) - 2 (2) x(2-1) or dy/dx = 2400 x^0 - 4 x^1 which is dy/dx = 2400 - 4 x
August 14, 2014

math
try volume Vnew = (x+2)(x+2)(x+2) big mess try area Anew = (x+2)(x+2) = x^2 + 4 x + 4 not this for sure try that perimeter thing how many edges? 4bottom +4top +4verticals = 12 edges 12 * 2 = 24 !!! winner
August 14, 2014

maths
suspect you mean 0.10 per 1/8 mile or 0.80 per mile c(n) = 1.80 + .8 n c(4.5) = 1.80 + .8 (4.5)
August 14, 2014

maths
I told you.
August 14, 2014

maths
surface area = area of base and top (same for both) + height*2 pi r so not the same and not twice volume = area of base * height ah ha, twice if you double height
August 14, 2014

Statistics
combinations of 15 taken six at a time 15!/ [6! (15-6)!] 15! /(9! 6!) 15*14*13*12*11*10 / (6*5*4*3*2) 7*13*11*5
August 14, 2014

maths
2.25 times volume = area of base * height height the same base 1.5*1.5 = 2.25
August 14, 2014

Physics
change in potential energy = m g h = work done = 2180 Joules/second * t
August 14, 2014

Physics
r omega^2 = 9.81 m/s^2 r = (6.9/2)*1000 = 3450 m so omega^2 = 9.81/3450 omega = .0533 radians/s (that is about 118 seconds /revolution or about 2 minutes per revolution)
August 14, 2014

Physics
force * time = change in momentum = m v
August 14, 2014

physics
x displacement = 50 cos 90 + 50 cos 245 = 0 -21.43 y displacement = 50 sin 90 + 50 sin 245 = 50 -45.3 = 4.68 displacement = sqrt (-21.4^2+ +4.68^2) = 21.9 meters x is negative and y is positive so quadrant 2 tan angle above x axis = tan^-1 y/-x = tan^-1 4.68/21.43 = 12.3 deg ...
August 13, 2014

math
25 + 12*15 = 205 .12 * 205 = 24.60 saved
August 13, 2014

Algebra
either way. (a*b)/c = (b/c)a = a b / c
August 13, 2014

algebra
Please, please, try to use standard notation Do you mean (3-s)^(1/3) = 3 ??????? if so raise both sides of the equation to the third power (3 - s)^1 = 3-s = 27 s = 3 - 27 s = -24
August 13, 2014

mathematics (word problems)
.5 x + .25 x = monitor + modem .25 x remains so .25 x = 200 + 150
August 13, 2014

whoops
(m-1/4)(.8) = 3 - 1.2
August 13, 2014

math
0.10 per 1/8 mile = 0.8 per mile miles = m (m - 1/4 ).10 = 3.00 - 1.20
August 13, 2014

math
volume of box = 4*3*2 = 24 ft^3 volume of brick = 8/12 *4/12 * 2/12 = 2/3 * 1/3 *1/6 = 1/3 * 1/3 *1/3 = 1/27 ft^3 24/ (1/27) = 648
August 13, 2014

Math
You try first.
August 13, 2014

math
17 * 10^-6 mm .0 0 0 0 1 7 move that dot 6 places right and you get 17
August 13, 2014

English
http://www.sparknotes.com/lit/flies/section12.rhtml
August 13, 2014

Geometry: Area and Volume Math
I mean volume of sphere :)
August 13, 2014

Geometry: Area and Volume Math
length in cm or meters or feet or elbows or thumbs area in cm^2 or m^2 or ft^2 or elbows^2 or thumbs^2 volume in cm^3 or m^3 or ft^3 or elbows^3 or thumbs^3 areas = multiple of two lengths volumes = multiples of three lengths of course those lengths might be the same for ...
August 13, 2014

Geometry: Area and Volume Math
length * width * height 6 * 6 * 6 = 6^3 = 216
August 13, 2014

math
sin Angle = 10/20 = .5 as we all know sin 30 degrees = .5
August 12, 2014

help AGAIN
Hopefully curiosity leads to an explanation. Hopefully sincerity leads to trustworthiness.
August 12, 2014

physics
time for phase 1 = 7/9.5 = .737 hr time for entire trip = 23/22 = 1.045 hr time for 16 km = 1.045 - .737 = .308 hr speed for 16 km = 16/.308 = 52 km/hr
August 12, 2014

chemistry
P V = n R T V = n (R T/V0 so volume is proportional to number of mos if P and T are constant we need three mols of H2 for every mol of N2 so there is exactly the right amount of each for every mol of N2 we will get 2 mol of NH3 so for every mL of N2 we will get 2 mL of NH3 so ...
August 12, 2014

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