Saturday
December 20, 2014

Posts by Damon


Total # Posts: 19,963

Health
no
August 21, 2014

math
32 gal/min * (60 min/ hr) * (4 qt/gal) = 7680 qt/hr notice that I multiply by things that are the same top and bottom but different units 60 min = 1 hr 4 qt = 1 gal I do the numerator and denominator to make the units I want to get rid of cancel and leave the new ones that I ...
August 21, 2014

math - and so on?
You did not say what he charged per mile after 2 miles
August 21, 2014

life sciences
http://humanorigins.si.edu/evidence/human-fossils/species/australopithecus-sediba
August 21, 2014

Math
2 L + 2 w = 12 so L = 6-w area = A = L w L w = (6-w)w = A w^2 - 6 w = -A find vertex by completing square w^2 - 6 w + 9 = -A+9 (w-3) = -1(A-9) max at w = L =3 and area = 9 By the way, you could have guessed that our rectangle would turn out to be a square.
August 21, 2014

Math
(y-4)/(x-0) = (-1-4)/(1-0) (y-4 ) = -5 x y = -5 x + 4 now sketch a graph of that
August 21, 2014

ALGEBRA
12 marbles first draw 3/12 = 1/4 second draw 5/11 1/4 * 5/11 = 5/44
August 21, 2014

math
if p </= 30 , then c = 750 if p >30 then c = 20 (p -30) + 750
August 21, 2014

college algebra
A 1/12 pool / hr B 1/24 pool / hr together 3/24 pool/hr so 24/3 = 8 hr/pool
August 20, 2014

algebra
sketch a graph !!! looks like a straight line with slope = -1 to me
August 20, 2014

Math
two are already decide. You have two more flips. What is the chance of getting one heads and one tails out of those two flips ? You have four possibilities HH HT TH TT two of those four work, TH and HT so I get 1/2
August 20, 2014

physics
Try using these: https://answers.yahoo.com/question/index?qid=20081123194116AA3FxdL use that for the average speed and standard deviation. Then he range is so narrow I would assume a normal distribution and use that average and standard deviation in the normal table rather ...
August 20, 2014

calc
A = 2 x (a^2+x^2)^.5 dA/dx = 2 x (2x)(.5)(a^2+x^2)^-.5) + 2 (a^2+x^2)^.5 = 0 for max or min
August 20, 2014

static and dynamics
force down slope = m g sin 34 so friction force = force down slope if it is not accelerating down slope.
August 20, 2014

math
z 2 x y z + 2 + x + 7 = 13 z is even or z = 2 w 2w + 2 + x + 7 = 13 2 w + x = 4 x must also be even or 0 x = 0 then w = 1 if x = 2 then w = 1 so if x = 0 then w = 2 2227 4207
August 20, 2014

math
4915/72 =
August 20, 2014

math
40 + 20 = 60 60 - 28/7 = 60 - 4 = 56 56 + 30/5 = 56 + 6 = 62 62 - 3 = 59
August 20, 2014

algebra HUH??
meaningless
August 20, 2014

physics
Calculate pressure halfway up the wall p = 1000 kg/m^3 * 10 m/s^2 * 2 m thrust on one wall = p * area
August 20, 2014

physics what is side and length of bottom?
.2 m square or .1 m square on bottom? I will assume bottom square size s and depth h pressure = density * g * h if h is .5 m (it is not clear what depth of alcohol is from sloppy wording of question. It is the depth that matters, not how high the container is off the ground.) ...
August 20, 2014

Science
24 g of Mg is how many mols of Mg ? so How many mols of O ? (Hint: MgO has exactly as many mols of O as of Mg , note of O at 16 g/mol, not O2 at 32 g/mol) so mass of O = mols of O * 16 g/mol
August 20, 2014

Chemistry
True :)
August 20, 2014

Connexus
If it were condensed it would be a liquid, not a gas.
August 20, 2014

physics
F = G Me m/R^2 = approximately m g because G Me/R^2 is pretty much constant around earth surface 1/R^2 Toward the center of mass of the object that is pulling it, for example toward earth center.
August 20, 2014

physics/ basic of statics
3 kg weighs 3*9.8 = 29.4 Newtons 5 kg weighs 5*9.8 = 49 Newtons say the 49 N force is in the x axis direction tthe 29.4 N force is 60 degrees toward the Y axis Sum of x forces= 49+29.4cos 60 = 63.7 N Sum of y forces = 29.4 sin 60 = 25.5 N magnitude = sqrt(25.5^2 + 63.7^2) = 68...
August 19, 2014

Science
I take that back, both question can be asked and then hypothesis posed: http://www.sciencebob.com/sciencefair/scientificmethod.php
August 19, 2014

Science
pretty much, although usually the word "hypothesis" is used instead of question. One tends to pose a hypothesis, then test so see if it works.
August 19, 2014

math
Remember back when when you were learning addition you had the commutative property of addition which means 2 + 3 is the same as 3 + 2 Now you are getting the same property for multiplication :)
August 19, 2014

math
you just did. The property means that 8 * 7 is exactly the same as 7 * 8 In other words the two factors commute, you can change their order without changing their product. This will be true until you get to multiplying matrices.
August 19, 2014

math
P = (60 - 22) x - 75 = 38 x = 75
August 19, 2014

math
(x+h)^2 + 2 = x^2 + 2 x h + h^2 + 2 the are getting you ready to find the derivative which is the limit as h -->0 of [f(x+h) - f(x) ]/h which here would be limit as h -->0 of (2 x h + h^2)/h or 2 x + h as h -->0 is 2x which is df(x)/dx
August 19, 2014

science
density is mass per unit volume if the volume of steel is the same and the mass more then the density of the steel is more. (strange by the way)
August 19, 2014

physics
dv/dt = -1/t^2 v = (1/t) + c 3 = 1 + c c = 2 v = (1/t) + 2 if t = 4 v = 2.25
August 19, 2014

physics
dv/dt = -kv dv/v = - k dt ln v = - k t + c e^ln v = v = e^(-kt +c) = e^c e^(-kt) when t = 0, v = Vo Vo = e^c e^0 = e^c so v = Vo e^-kt
August 19, 2014

physics
2 seconds rising and 2 seconds falling h = (1/2)g t^2 falling 10 = (1/2) g (4) = 2 g g = 5 m/s^2
August 19, 2014

physics
it evidently goes forward a distance 3d then back a distance 2d to end up a displacoutup to be negative. deceleration phase out to 3 d t1 = time out to 3 d v = Vi + a t1 0 = Vi + a t1 so t1 = -Vi/a 3 d = Vi t1 + (1/2) a t1^2 3d = -Vi^2/a + .5 Vi^2/a = -.5Vi^2/a d a = -(1/6) Vi...
August 19, 2014

Language Arts
I can not see your italics but suspect it is the "ing" and D is correct. http://en.wiktionary.org/wiki/present_participle
August 19, 2014

math
5 y + 7 x = 31 x y 5 y + 7 x = 29 x y well, (0,0) would work but then we would be dividing by zero in the original.
August 19, 2014

English
"His questions revealed an intelligence" seems to be the main idea so what is the rest ? http://www.chompchomp.com/terms/relativeclause.htm
August 19, 2014

english
http://www.merriam-webster.com/dictionary/tally
August 19, 2014

P.E
I figure my natural crabbiness is likely to be fatal, perhaps even to me.
August 19, 2014

P.E
Certainly
August 19, 2014

english
Let me see: He spread the rumor widely. ------> He spread the rumor most widely ?
August 19, 2014

math
There are six numbers so add them all up and divide the sum by six.
August 19, 2014

Philippine history
http://www.academia.edu/4833169/Continued_Filipinization_in_the_Late_20th_Century_The_Case_of_the_Ateneo_de_Manila_University_1968-1991
August 19, 2014

Philippine history
http://prezi.com/cfw8l09tjkas/filipinization-policy/ When the US defeated the Spanish in the Spanish American War, the Philipines ceased to be a Spanish colony and came under the US. The US made an effort to let the indigenous people take over ruling their islands replacing ...
August 19, 2014

Physics
All I can do is tell you the method. call M1 the mass of the one that is on string at 50 degrees from vertical (aI assume from vertical Then gravity force down slope is M1 g cos 50 T is up slope net force down is (M1 g cos 50 -T) same deal for M2 net force down is (M2 g cos 30...
August 19, 2014

Physics
I do not understand this geometry. Is the big one trying to drop down a 53 deg slope and the little one being dragged up a 30 degree slope or what?
August 19, 2014

Physics
The table is three football fields long and three football fields high? I bet it was 0.15 seconds actually :)
August 19, 2014

Physics
big table :)
August 19, 2014

Physics
F = 20 * 9.8 m = 50 + 20 = 70 a = F/m = 2.8 m/s^2 force on falling 20 kg mass = 20 (9.8) - T = m a = 20(2.8) so T = 140 Newtons d = (1/2) a t^2 = (1/2) 2.8 (225) = 315 are you sure you did not mean 1.5 seconds?
August 19, 2014

science
probably at least on a cell scale.
August 19, 2014

Second law of motion
Net force up = 35 - 25 = 10 Newtons F = m a m = 25/9.8 = 2.55 kg so a = 10 / 2.55 = 3.92 m/s^2
August 19, 2014

Physics
Good grief, English units, have to put mass in slugs and use seconds and pounds and feet. (Back to freshman year in 1955) change in speed = 40 miles/ hr *5280 feet/mile * 1 hr/3600 seconds = 58.7 feet per second mass in slugs = 3000 lb /32 ft/s^2 = 93.8 slugs F = change in ...
August 19, 2014

Science
north velocity = 30 (assume west wind so blowing plane east) east velocity = 40 total speed = sqrt (30^2+40^2) = 50 km/hr tan angle east of north = 40/30 angle east of north = 53.1 or about northeast by east (NExE)
August 19, 2014

Physics
F down slope = m g sin 35 a = F/m = g sin 35 = 9.8 sin 35
August 19, 2014

math
a + a r + a r^2 + a r^3 + a r^4 ....+a r^(n-1) so a r = 1.5 a r^4 = .1875 a = 1.5/r (1.5/r) r^4 = .1875 r^3 = .125 r = .5 a = 1.5/.5 = 3 so 3 + 1.5 + .75 ......
August 19, 2014

science
Huh ?
August 19, 2014

Parabola
axis of symmetry is halfway between 2 and 3 or x =2.5 to get the zeros of y at x = 2 and 3 y = k (x-2)(x-3) to get y = 6 at x = 0 6 = k (-2)(-3) k = 1 so y = x^2 -5 x + 6 (answer) check if vertex is at x = 2.5 by completing the square y -6 = x^2 - 5 x y - 6 + (5/2)^2 = x^2 - 5...
August 19, 2014

Maths
(1-e^-x) integral (1-e^-y) dy from 1 to 2 (1-e^-x) [ y + e^-y ] at 2 - at 1 (1-e^-x) [ 1 + (e^-2 - e^-1) ] (1-e^-x) [ .767 ] integrate that dx from 1 to 3 [ .767 ][ x + e^-x] at 3 - at 1 [ .767 ] [ 2 + (e^-3 - e^-1) ] [ .767 ] [ 1.68 ] 1.29 divide by area to normalize area = 2...
August 19, 2014

algebra
I do not dare because I bet you have typos. For example I would be surprised if -1^2 is not supposed to be (-1)^2.
August 19, 2014

physics
no s = -16 t^2 + 64 t If the ball left the ground with velocity + 64 ft/x then it returns to earth with velocity -64 ft/s. Your parabola is symmetrical and the vertex is at the top,
August 19, 2014

Math
Sorry, can not email to you. The word compass bearing is used correctly here. tangent of angle north from west axis = 70/145 tan^-1 (70/145) = 26 deg so bearing = 270+26 = 296 degrees clockwise from North this is approximately west north west
August 18, 2014

math
Henry, The 30 degrees is from North (the y axis), not from east (the x axis as in math convention).
August 18, 2014

math
^&%#*& mathematicians ! He flies on a HEADING of 030 east of north, NOT a bearing. You take a bearing on something, its direction from you. You sail or fly a compass HEADING. anyway East components are 90 sin 30 +150 =90 * (1/2) + 150 = 45 + 150 = 195 km east of start
August 18, 2014

math
actually the express train from Delhi to Meerut seems to go about 44 km/hr by the way: http://indiarailinfo.com/search/new-delhi-ndls-to-meerut-cantt-mut/664/0/1546
August 18, 2014

math
they approach each other at 180 km/h 75 km * (1 h/180 km) = .4167 h * 60 min/h = 25 minutes so 8:25 am
August 18, 2014

social studies
http://dictionary.reference.com/browse/xenophobia
August 18, 2014

social studies
Thank you Lexie Bowles. That was fun !
August 18, 2014

social studies
http://civilliberty.about.com/od/immigrantsrights/tp/Xenophobia-in-United-States.htm
August 18, 2014

social studies
http://en.wikipedia.org/wiki/Anabasis_%28Xenophon%29
August 18, 2014

math
50 in 125 and 30 in 90?
August 18, 2014

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

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