Sunday
November 23, 2014

Posts by Damon


Total # Posts: 19,402

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

math (cant figure it out)
11 numbers, 6 of which are even if you count 0 as even (there are evidently 10 spaces between numbers but 11 numbers) so 6/11 but the question is poorly worded.
June 10, 2014

My Final Algebra 1 Question
a. x must be greater than 0 (undefined for x = 0) so x = 0 is not in the domain (infinite number of teachers) y, must be greater than 2 so range is 2 to very large (for small cost per teacher.) If x is a dollar per teacher, then y = 202 which seems a reasonable upper limit. b...
June 10, 2014

Physics
I agree with 1/2
June 10, 2014

math
(a+b)/2 = 9 so a+b = 18 sqrt ( a b) = 3 sqrt 5 so a b = 9*5 = 45 well so b = 45/a and a + 45/a = 18 or a^2 - 18 a + 45 = 0 ( a-15)(a-3) = 0 a = 15 or 3 so one of them is 3 and one of them is 15
June 10, 2014

HISTORY
Lincoln issued the proclamation under his powers as commander in chief of the US military ass an act of war. He had no authority to remove property from people with whom we were not at war.
June 10, 2014

math
arithmetic mean = (10+40)/2 geometric mean = sqrt (10*40) = 20
June 10, 2014

HISTORY
From Wikipedia: In the mid and late 1840s, immigrants from Ireland and Germany streamed into the city, swelling the population of Philadelphia and its suburbs.[52] In Philadelphia, as the rich moved west of 7th Street, the poor moved into the upper class' former homes, ...
June 10, 2014

math
value = 1540 *(1/2)^(n/4) when n = 0, years, cost = 1540 for person 1 when n = 4 years, cost = 1540/2 for person 2 when n = 8, years, cost = 1540/4 for person 3 etc
June 10, 2014

Maths
Since it asks for depth wrt average, we do not need the 4 m average but only how much it departs from average at t = 0, d = -2 (low tide, 2 feet below average) d = -2 cos 2 pi t/T since T = 12 hours is given d = -2 cos (pi t/6)
June 10, 2014

Algebra 1--Please, help me!
(2x-20)(x+1) for example would be 2 x^2 - 18 x - 20 (2 x - 10)(x + 2) would be 2 x^2 - 6 x - 20 so 18 or 6 would work
June 10, 2014

calculus
(x+3)^2 = p (y-q) g = x + 7 when g = 0, x = A 0 = A + 7 A = -7 so A is 4 to the left of -3 therefore B is 4 to the right of -3 or at B = +1 so g = 7 at x = 0 so C = 7 A = (-7,0) B = (1,0) C = (0,7)
June 10, 2014

Algebra 1-- Please, check my answers!
As far as I know, yes
June 10, 2014

Algebra 1-- Please, check my answers!
Now wait a minute. Somewhere in your text book it says that if the denominator of a fraction is zero, that spot must be excluded from the domain of the function since the answer is undefined. Try dividing some number by zero on your calculator. Answer is "c". I had ...
June 10, 2014

Algebra 1-- Please, check my answers!
5. Which if the following is a true statement about the function y = 1/x? a. The domain is all real numbers. b. The range is all real numbers. c. The domain is all real numbers except 0. d. The range is all real numbers except 1. A: a? ============================= No, ...
June 10, 2014

math
Ah, two of us posted answers above.
June 9, 2014

math
change percent to decimal fraction by dividing by 100 so we mean .25 * 250 off 62.50 off 250 - 62.50 = $ 187.50 alternatively 100% - 25% = 75 % 75/100 = .75 .75 * 250 = $ 187.50 againg
June 9, 2014

Algebra 1--Please, check my answer!
When x = 6 (x-6) = 0 so y = 0 when x = 6 That is when it hits the x axis
June 9, 2014

Algebra 1--Please, check my answer!
If x = 6, bang if x = 6 bang so at ONE point x = 6 which is the vertex of the parabola. It just grazes the x axis and both roots are right there.
June 9, 2014

Algebra II
smallest = s biggest = b medium = m b = s + 90 m = s + 30 s + m + b = 180 s + s + 30 + s + 90 = 180 3 s = 60 etc.....
June 9, 2014

Calculus
yes
June 9, 2014

Calculus
See Baggins, Bilbo, "There and Back Again".
June 9, 2014

Calculus
Your velocity is zero at t = 3 !!!!! right in the middle of your range. It reversed direction midstream You calulated displacement (where it moved to which was nowhere) instead of how far it went (distance moved) do t = 0 to t = 3 then t = 3 to t = 6 add the ABSOLUTE VALUES
June 9, 2014

physics
How much energy should it have? m g h = 1.6 * 9.81 * 2.9 How much does it have? (1/2) m v^2 = (1/2) * 1.6 * (2.8)^2 so subtract
June 9, 2014

math study guide
1. no idea, do not have data 2. I get 8/20 = .40 3. again no data but in theory 3/4 4. 15/100 = 3/20 5. 20/100 = x/50 ??? Hey, are you just guessing or what?
June 6, 2014

Science
You are welcome.
June 6, 2014

Science
a) yes b) yes c) yes d) yes, traveling wave, air particles moving
June 6, 2014

Math
19 marbles p(first is purple) = 2/19 now 18 marbles, what is p(yellow) first p(yellow) = 5/18 so p(NOT yellow) = 13/18 p purple then not yellow) = 2/19 * 13/18
June 6, 2014

Math
p(not 5) = 5/6 then p(green) = 1/6 so 5/6 * 1/6 = 5/36
June 6, 2014

Math
Permutations of 7 items taken 3 at a time. The order matters so it is permutations, not combinations. Look at "ordered subsets" in the link: http://dwb4.unl.edu/Chem/CHEM869N/CHEM869NMats/Permutations.html 7! / (7-3)! = 7!/4! = 7*6*5 = 210
June 6, 2014

Math
There are four possible results A. Mike and Dave both miss B. Mike hit, Dave miss C. Dave hit, Mike miss D. both hit p mike hits = .6 so misses = .4 p dave hits = .3 so misses = .7 So p(A) = .4 * .7 p(B) = .6 * .7 p(C) = .3 * .4 p(D) = .6 * .3 We want p(A) + p(D) = .28 + .18...
June 6, 2014

Math
say 8/64 are red then probability of two red is 8/64 * 7/63 = 1/8 * 7/63 the next one is yellow, again same answer but now twice the probability so in the end 8 * 1/8 * 7/63 = 7/63
June 6, 2014

Science
or yes, yes :)
June 6, 2014

Science
35 * g = weight weight * distance raised = work in which is exactly the increase in potential energy
June 6, 2014

Algebra ll
You are welcome.
June 6, 2014

Algebra ll
yes
June 6, 2014

Algebra ll
(x - a)^2 + (y-b)^2 = r^2 for circle of radius r and center at (a,b)
June 6, 2014

Math
This is more fun every hour! Four ways now :)
June 6, 2014

Math
LOL !!!
June 6, 2014

Math
sketch a graph first If it goes through (0,4) and (2,4) I suspect that the center is on the line x = 1 (x-1)^2 + (y-b)^2 = r^2 when x = 0, y = 4 1 + (4-b)^2 = r^2 when x = 2, y = 4 1 + (4-b)^2 = r^2 again of course when x = -5, y = 0 36 + b^2 = r^2 so 1 +(4-b)^2 = b^2+36 1 + ...
June 6, 2014

Science
8.b yes 9.c Huh? 21/21 = 1 10.a I do not think so. She, not the wheelbarrow, supplied the work. If it weighed 35 N and she lifted it 2.5 meters, then D would be correct. The problem is poorly written. It is not clear if the force is in the direction of motion.
June 6, 2014

physics
PE = - G m Me/R where G = 6.67 * 10^-11 Look at change in potential energy at R = 6.38*10^6 and at 6.38*10^6 + .120 *10^6 meters I bet it would not be far off to use m g h where g = 9.81 m/s^2 :) because 120 km is not far compared to Rearth
June 6, 2014

calc
draw a sketch If the interval means from x = -1 to x = +2, then it is also from y = 2 to y = 8 As I read it then this base is a triangle with corners at (-1,8) (2,2) and (-1,2) The volume of the figure would then be 2 times the area of the base Area of base = (1/2) (3)(6) = 9 ...
June 6, 2014

pre calc
(x+5)^2 = 4 (y + 1/2) vertex at (-5, -1/2) so for the left half x is always less than (to the left of) -5 an y is above -1/2 I do not know what else to say
June 6, 2014

physics
F = m g = G M m /r^2 so g = G M/R^2 double m, double g double R , divide by 4 so 15.5 / 2
June 6, 2014

Chemistry
In a liter you have .1 mol of HCl .1 * (35.5 + 1) = 3.65 grams/liter so in half a liter you have 1.825 grams of HCl
June 6, 2014

Math
2(117) - 1 is not 2001
June 6, 2014

Math
1, 3 , 5 , 7 , 9 ....... first is 1 = 2 - 1 second is 3 = 4 - 1 third is 5 = 6 - 1 number (n) = 2 n - 1 number (117) = 2(117) - 1
June 6, 2014

MULTIPLY. WRITE EACH PRODUCT IN SCIENTIFIC NOTATIO
a^x * a^y = a(x+y) a^x / a^y = a^x * a^-y = a^(x-y)
June 6, 2014

algebra
-6x^2 + 7 x just to be sure you followed all that
June 6, 2014

physics
Fx * x = 40 cos 28 * 100 foot pounds
June 6, 2014

Math
p(not red) = 1 - p(red)
June 6, 2014

Calculus
2 W + L = 40 so L = 40 - 2 W A = W L = W (40 - 2 W) = 40 W - 2 W^2 dA/dW = 40 - 4 W W = 10 so yes
June 6, 2014

mathematics
dy/dx = 6 x^2 + 15 x^4 then y = 2 x^3 + 3 x^5 + c find c 7 = 2(8) + 3(32) + c 7 = 16 + 96 + c c = -105 so y = 2 x^3 + 3 x^5 - 105
June 6, 2014

Calculus
A = x^2 = (3t+1)^2 = 9 t^2 + 6 t + 1 dA/dt = 18 t + 6 when t = 2 dA/dt = 36 + 6 = 42
June 6, 2014

algebra
excuse me, typo like 2^2 * 2^3 = 2^5 = 32 which is also 4*8
June 6, 2014

algebra
x^(9-2) = x^7 because x^a * x^b = x^(a+b) like 2^2 * x^3 = 2^5 = 32 which is also 4*8
June 6, 2014

physics
680C = 273+680 = 953 K 220 C = 273 + 220 = 493 K e = (953-493)/953 = .483 IF and ONLY IF it is a Carnot cycle heat engine (maximum efficiency)
June 6, 2014

math
36/60 = 6/10 = 3/5
June 5, 2014

science pls help asap!!!
the A horizon is topsoil wind removes topsoil mostly by abrasion loess is soil settled from the wind often in the lee of an obstacle. I am not sure dunes need an obstacle.
June 5, 2014

math
A) correlation coefficient is between -1 and +1 , not 1.09 B) negative coefficient means that y is pretty well correlated with negative x. It is pretty much a straight line but with negative slope. like y = -5x + 3 http://www.dmstat1.com/res/TheCorrelationCoefficientDefined.html
June 5, 2014

math
You got three even numbers (4 , 2 and 6) out of eight tosses.
June 5, 2014

math
5! 120
June 5, 2014

math
4*6*3 = ?
June 5, 2014

Physics
Fx dx + Fy dy (-3 * 3.6) - (7.6 * -2) 4.4
June 5, 2014

algebra
You are welcome.
June 5, 2014

algebra
I did. It is not a straight line. answer is no
June 5, 2014

algebra
what is (25-17)/(2-1) ? 8 what is (1 - -7) /( -1 - -2) ? 8/1 = 8 humm looks like slope = 8 so far but what about (17 -8)/ (1 - 0) = 9 !!!!! oh my, not the same slope crash not on a straight line of constant slope
June 5, 2014

algebra
Oh ! 5*3^1 = 15 5*3^2 = 5*9 = 45 45* 3 = 135 135 * 3 = 405
June 5, 2014

algebra
nor do I unless you have a value for n
June 5, 2014

algebra
You are welcome :)
June 5, 2014

algebra
If x = 2 2 * 1^2 = 2*1 = 2
June 5, 2014

Science
Hey, in orbit there is no air around you and therefore no air pressure. You must maintain approximately atmospheric pressure inside if manned. If unmanned, you still must make sure nothing blows up when the outside pressure goes to zero. There is no nice layer of air to ...
June 5, 2014

Science
It sounds like you might have proposed a space mission as a class project or something and the question is asking why it should be funded and how it would work with other efforts.
June 5, 2014

Science
1200 * 15 Joules 2500 * 16 Joules work = Force component in direction of motion * distance moved. I wonder why you are asking. This should be in the first sentence of the first paragraph of your text on the subject.
June 5, 2014

science 1 question!!!
Number 1 is really an English comprehension question. Rivers generally run down valleys. therefore I am at a loss to understand why a valley glacier would spread out over a continent while a continental glacier would stick to a spot in the mountains.
June 5, 2014

science
Potential energy gain = m g h where h is the distance lifted
June 5, 2014

physics
I assume you mean in a centrifuge? If so Ac = v^2/R so g = v^2/R v = sqrt ( R g) = sqrt (9.81 R)
June 5, 2014

Physics
The loudness is the amount of power passing through a square meter of area surrounding the source. As you get further from a constant power source, the loudness decreases because the area of a sphere surrounding the source increases. ( You know that. As you get further from a ...
June 5, 2014

physics
get V from momentum (75 + 52) V = 75 (1.8) calculate V calculate (1/2) m V^2 friction force = .042 * m * g friction force * distance = (1/2) m V^2 or actually m cancels .042 g d = .5 V^2
June 4, 2014

physics
(1/2) m v^2 = (1/2) k x^2
June 4, 2014

physics
Hey, you have done several of these now. Try
June 4, 2014

Math
cost per unit = cpu = C(x) / x = 36,100/x + 100 +.01 x d cpu/dx = 0 at min = -36,100/x^2 + .01 .01 x^2 = 36,100 x^2 = 3,610,000 x = 1900 units now go back and get cpu = 36,100/1900 + 100 + .01(1900) = 2019
June 4, 2014

Math
2 dimensional with 3 or more sides side angle
June 4, 2014

Physics
k = 30 N/.2 m = 150 N/m PE of spring = (1/2) k x^2 = 75(.04)=3 Joules normal force = m g friction force = .4 m g work done against friction = .2 *.4 * mg = .08*.25*9.81 = .196 Joules so Ke left = 3 - .196 = 2.8 Joules (1/2) m v^2 = 2.8 calculate v
June 4, 2014

Precalculus
6 letters if start with A so 5 left c(5,3) = 10 10 more start with I so 20 total others similar
June 4, 2014

Precalculus
2a 9*10*10 = 900 2b 4 * 5 * 5 2c 9 * 1 * 10
June 4, 2014

Precalculus
c(20,5) = 20!/(5!*15!) = 20*19*18*17*16 /(5*4*3*2) = 15504
June 4, 2014

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