Thursday
October 23, 2014

Posts by Damon


Total # Posts: 19,012

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

Precalculus
1. NO The order does not matter, Disney first or white mountains first so COMBINATION C(20,5)
June 4, 2014

Math
x = 15 - 2y x^2 = 225 - 60 y + 4 y^2 F = 5 y^2 -60 y + 225 dF/dy = 10 y - 60 zero when y = 6 then x = 3 is that min or max? d^2F/dy^2 = 10 so it is min F here = 9+36 = 45 check ends if x = 0 y = 7.5 and F = 56 1/4 if y = 0, x=15 and F = 225 ok, done
June 4, 2014

Math - Business Calc.
Hey, use that h, calculate L and w find L W h
June 4, 2014

Math - Business Calc.
L = 17 - 2 h W = 5 - 2 h V = L W h V = (17-2h)(5-2h)h = (17-h)(5h-2h^2) dV/dh = (17-h)(5 - 4h) +(5h-2h^2)(-1) = 85 - 73 h +4 h^2 -5h + 2 h^2 = 85 - 78 h + 6 h^2 where is that derivative zero? h = [ 78 +/- sqrt (6084-2040) ]/12 h = [ 78 +/- 63.6 ] / 12 h = 11.7 impossible, ...
June 4, 2014

physics
hey, just like the last one ! PE = (1/2) k x^2 PE = m g h = m g d sin 30 = .5 m g d if d is distance along the ramp
June 4, 2014

Math
sum of degrees of exterior right turns = 360 (all the way around) 360/5 = 72 so each interior angle is 180 - 72 = 108 and 5*108 = 540
June 4, 2014

physics
loss of potential energy by ball = m g (1.5 + x) gain of potential energy by spring = (1/2)(150)x^2 so 2.2 * 9.81 *(1.5+x) = 75 x^2 21.6 x + 32.4 = 75 x^2 or 75 x^2 - 21.6 x - 32.4 = 0 x = [21.6 +/-sqrt(467+9720) ]/150 x = [ 21.6 + 101 ] /150 x = .817 meter
June 4, 2014

physics
F = .15 * 45 a = F/m
June 4, 2014

Physics
first ball stops in 2.3/2 = 1.15 seconds 0 = Vi - g t Vi = 9.81 (1.15) = 11.3 m/s second ball has same Vi Vi = V sin 42 V = 11.3/sin 32 = 21.3 m/s
June 4, 2014

MATH PLZ HELP
one every 15 minutes is 4 per hour
June 4, 2014

Physics
0 = 0 + Vi t - 4.9 t^2 Vi = 9.95 sin 35 = 5.71 so 0 = 5.71 t - 4.9 t^2 t = 0 or t = 1.16 t = 0 was zero height when it started t = 1.16 seconds is zero height when it landed
June 4, 2014

Physics
That is how much negative charge it is missing. (How much positive charge it has)
June 4, 2014

Physics
F = q E = m a E = m a/q m is given q = 5*10^3 * electron charge a is given
June 4, 2014

Physics
(2L/3)(3W)(3H)
June 4, 2014

civics
I do not know. What is the correct C?
June 4, 2014

typo
You B and C are the same and you left out the right choice.
June 4, 2014

science
This is oversimplified. Yes, you need data, but you also need a mathematical model and theory.
June 4, 2014

History
Oligarchy means government by a select few. Therefore I would say B. However it is not necessarily a political party. It could be just a group of rich people or guys with guns.
June 4, 2014

physics
normal force = 55 g friction force = .11 * 55 g acceleration = F/m = -.11 * 55 * g /55 = -.11 g = -1.08 m/s^2 v = Vi + a t 0 = 5.6 - 1.08 t t = 5.2 seconds to stop go at average speed (5.6 /2) for 5.2 seconds d = 14.5 meters
June 4, 2014

Delcambre High
(4/15) / (1/3) multiply top and bottom by 15 4 / 5
June 4, 2014

civics
Mexicans often migrate North to get jobs. Of course Texas and half of California and Arizona and New Mexico ... were Mexico.
June 4, 2014

civics
Halifax, Quebec, Montreal Ottawa, Toronto --- Vancouver Which are in the North of Canada on the Arctic Ocean ?
June 4, 2014

civics
It certainly is NOT A !!!! Hey, take a good look at where cities are in Canada Come on, why do Mexicans move North ? Is New York or Chicago or Montreal or Toronto subtropical or tropical ?
June 4, 2014

math
now wait a minute, time to learn this stuff: In a right triangle: sin theta = opposite / hypotenuse cos theta = adjacent / hypotenuse tan theta = opposite / adjacent so here we have hypotenuse is ladder, 13 adjacent = along ground = 3.7 so cos theta = 3.7/13
June 4, 2014

math
tan theta = 5.5 / d
June 4, 2014

civics
By the way, cost on a ship for freight is much less per mile than by any other method.
June 4, 2014

civics
That would be my answer, but you could disagree if you say why :) I see oceans at the borders, not rivers or lakes for the most part (except the Rio Grande and some Great Lakes of course)
June 4, 2014

civics
Well, from Halifax to San Diego, North America abounds in seaports on the Atlantic and Pacific although Mexico has relatively small ones.
June 4, 2014

Math
total length = 20 + 10 = 30 total width = 10 + 10 = 20 so total area = 600 but area of photo itself = 20*10 = 200 so frame area = 400 400/600 * 100 = 67 % is frame
June 4, 2014

chemistry
PV = n R T = constant so P1 V1 = P2 V2 565 (235) = P2 (215)
June 4, 2014

physics
We do not know yet if the top block slips. First, assume it does not slip. F = m a 30 = (4+2) a a = 5 m/s^2 Now How much force is required to accelerate the top block at 5 m/s^2? F = 2 (5) = 10 N required How much do we have? Fnormal = m g = 2*9.81 = 19.62 N so friction max...
June 4, 2014

statistics
http://davidmlane.com/hyperstat/z_table.html here z = (.62 - .60) / .02 = 1
June 4, 2014

Math
(p q)^3 ( q + p q^2) 3^3 ( q + 3 q) 3^3 (4q) 27 (4 q) 108 q
June 4, 2014

Math
total marbles = 6 + 10 + 9 = 25 first draw 9/25 second draw 8/24 so (9/25)(1/3) = 9/75
June 4, 2014

science
v= 3^3 = 27 cm^3 rho = m/v = 54/27 = 2 grams/cubic centimeter
June 4, 2014

Science
1. b agree 2. a and d, yes, double covalent 3. b, d e yes, but highly radioactive metal 4. d yes 6. yes a, b 8. not sure about 8 but would guess group 1 (b) 9. No, a row is a "period" (b)
June 4, 2014

physics
dx/dt = b t^2 so x = (1/3) b t^3 + starting x
June 4, 2014

science
mass of one liter of water = 1 kg Archimedes says: F = m g = 1 kg * 9.81 m/s^2 = 9.81 Newtons
June 4, 2014

Algebra - Steve!! Help!
By the way, that would be impossible without changing the pressure as well.
June 4, 2014

Algebra - Steve!! Help!
V T = k *** IF *** I assume this is true then: 500 * 2.5 = k = 1250 so 100 T = 1250 T = 12.5 C I guess that is the answer they want, but in fact V T = constant ONLY if you use degrees KELVIN which is degrees C + 273 so really 500 * 275.5 = k = 137,750 so 100 T = 137,750 T = ...
June 4, 2014

Physics
Huh ? Are you doing relativity? The force on it is constant, q*E so the acceleration is constant, forever if it were not limited by approaching the speed of light.
June 3, 2014

Physics
You are welcome.
June 3, 2014

Physics
Watts is power (Joules/second)
June 3, 2014

physics
6000 + 2500 = 8500 kg = m m g = weight = 9.81 * 8500 F = weight + m a F = 9.81* 8500 + .5 * 8500 = 87,635 N T = 9.81*2500 + .5 * 2500 = 25,775 N
June 3, 2014

physics
Ac = v^2/r if you increase v, then v^2 increases by the square of the ratio new Ac = (16/9) old Ac = (16/9)12 = 21.3 m/s^2
June 3, 2014

Physics
1/R = 1/5 + 2/5 + 1/10 = (2+4+1)/10 = 7/10 so R = (10/7) k Ohms =1.44 k Ohms
June 3, 2014

math 1 question!!!!!!
- (3/5) a
June 3, 2014

math
y = m x 9 = m * 5 m = 9/5 so y = (9/5) x or 5 y = 9 x ------------------------- or easier way x/y = 11/1.5 11 y = 1.5 x
June 3, 2014

Physics
You are welcome.
June 3, 2014

Physics
V/R = i = 45/15 = 3 amps
June 3, 2014

Math
combinations of 7 taken 4 at a time C(7,4) = 7! /[ 4!(3!)] = 7*6*5/(3*2) = 35
June 3, 2014

Physics
T = tension mass 1 = 30/g mass 2 = 20/g for mass 1 m a = m g - T (30/g)a = (30/g) g - T for mass 2 (20/g) a = T - (20/g)g add the two equations (50/g) a = (10/g) g so a = g/5 or about 9.81/5 = 1.96 m/s^2 that is Part B go back and get T for part A then for part C chain tension...
June 3, 2014

Calculus
2 x^2 + 4 x h = 600 h = (600 -2 x^2 )/4x or h = (300 - x^2)/2x v = x^2 h v = (1/2)( x)(300 -x^2) v = (1/2)(300 x - x^3) dv/dx = (1/2) (300 - 3 x^2) = 0 for max or min so x = 10 then x^2 = 100 h = 10 v x^2h = 1000
June 3, 2014

science
For electricity: coal, wood, gas, running steam generator , or diesel generator or solar, geothermal, water wheel, wind turbine choice depends on where you are, do you have water power available? geothermal handy? strong winds? Southern exposure to sun?
June 2, 2014

rounding
Yes
June 2, 2014

Algebra
4 sqrt 10 - 1 sqrt 10 = 3 sqrt 10
June 2, 2014

Algebra
well, it is hard for me to graph here so eliminate y by subtracting the second equation from the first x^2 + 5 x -50 = 0 (x-5)(x+10) = 0 so x = 5 or x = -10 if x = 5, then y = -10 if x = -10 then y = 35
June 2, 2014

Algebra
if -3m = 0, then the whole thing is 0 so if m = 0, the whole thing is 0 if (2m-5) is 0, the whole thing is 0 so if m = 5/2, the whole thing is 0 so the solutions are m = 0 and m = 5/2
June 2, 2014

when the energy of a sound wave is transferred to
Hey, what do you think the answers are and why ? You can figure it out even if you do not know much physics.
June 2, 2014

math HELP!!!!!!
You are welcome :)
June 2, 2014

math HELP!!!!!!
16/40 = x/700 2/5 = x/700 x = 1400/5 = 280
June 2, 2014

physics
m g h
June 2, 2014

math HELP!!!!!!
Yes, C
June 2, 2014

math HELP!!!!!!
no review your text about valid sampling and bias
June 2, 2014

MATH!!!
V = 156 + 4.5 (t - 12)
June 2, 2014

Algebra
16 t^2 -20 t - 6 = - h in obsolete English units when does h = 0? t = [ 20 +/- sqrt (400 + 384) ] /32 t = [ 20 +/- 28 ] /32 t = 48/32 = 1.5 seconds (ignore the negative t) for vertex complete the square assuming no calculus may be used 16 t^2 -20 t = - h + 6 t^2 - (5/4) t = -h...
June 2, 2014

Math
p(f) = 3/20 p(first) = 3/20 = .15 p(second) = 2/19 = .105 p first and second = .15 * .105 = .0158 first fail, second pass = 3/20 * 18/19 first pass second fail = 17/20 * 3/19
June 2, 2014

Physics
.050 Vo = 1.050 v so v = .0476 Vo initial Ke = (1/2)(.05)Vo^2 final Ke = (1/2)(1.05)v^2 100 (.05 Vo^2 - 1.05 v^2) /.05 Vo^2 100 (.05 Vo^2 - .00238 Vo^2)/.05 Vo^2 = 95.2 % of initial energy is lost
June 2, 2014

Physics
(1/2)(1200)(900) = 540,000 joules m g h = 1200 * 9.81 * h = 540,000 h = 45.9 meters
June 2, 2014

College Algebra
x (x-9) =0 x = 0 and x = 9 are correct ps I bet they meant: x^2 - 9 = 0 (x-3)(x+3) = 0 x = 3 or x = -3
June 2, 2014

Math
arithmetic series see http://www.mathwords.com/a/arithmetic_series.htm here a1 = 30 and d = 4 and n = 10
June 2, 2014

What is the coefficient of x?
-5
June 2, 2014

Physics
R = 10 + 8 + 27 i = 9/R for each Vn = i * Rn the sum of Vn better equal 9
June 2, 2014

Math
a + c = 390 a = 2.25 c so 2.25 c + 1 c = 390, solve for c then for a Revenue = 8 a + 3 c
June 2, 2014

Math
You are welcome.
June 1, 2014

Math
tan angle = 34/12
June 1, 2014

science
When you post a question again and again and no one replies, perhaps there is something missing in the question that renders it incomprehensible. We have no idea where or what you are talking about, on a beach or in a bottle or what else is behind your question.
June 1, 2014

algebra2/ Trigonometry
24+22+14+12 = 72 marbles yellow = 14/72 = .1944.... or about 19.4 % do the others the same way
June 1, 2014

Geometry
You are welcome.
June 1, 2014

Geometry
Volumes scale as the CUBES of corresponding lengths of similar figures (25/35)^3 = (5/7)^3 = 125/343
June 1, 2014

typo
I have no idea what you mean there are about 6*10^23 anythings per mole just like there are 12 anythings per dozen
June 1, 2014

trigonometry ans.
You are welcome.
June 1, 2014

trigonometry ans.
right, you asked for nearest foot
June 1, 2014

trigonometry ans.
tan 53 = height/distance yes, 66 to nearest foot The right angle is at the foot of the tree. ALWAYS draw a picture tan 53 = opposite (tree) / adjacent(along ground the hypotenuse is along your line of sight, not used here
June 1, 2014

physics
momentum after momentum before sum of m after v after = sum of m before v before .16 (27.5) + (68) v = 68.16 (2.55) solve for v second skater: (60.5+.16) v = .16(27.5) solve for second skater v
June 1, 2014

Geometry
ok, always sketch a graph
June 1, 2014

Geometry
It gets smaller.
June 1, 2014

help
You are welcome.
June 1, 2014

help
tan 12 = 40/d d = 40/tan 12 = 188 meters ! If that diver is wearing a hard hat, he is going to be a wreck himself by the time he gets there and it will take so long that he will need to make decompression stops upon ascent to avoid getting the bends. Move the stupid ship !
June 1, 2014

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