Monday
January 26, 2015

Posts by Damon


Total # Posts: 20,417

Physics
Try to draw a wavelength of .75 meters in your 1 meter string without a crest, not a node, at one end. D is allowed for sure, the lowest resonance. Draw it
November 28, 2014

Calculus
You are welcome.
November 28, 2014

Calculus
dy/dx = slope = 3 x^2 - 6 x + 5 where is that max or min ? where its derivative is 0 d^2y/dx^2 = 0 = 6 x - 6 so x = 1 is that a max or a min? take the ext derivative, if + it will be headed up and a min. d^3y/dx^3 = 6 that is positive so the min slope is at x = 1 that slope is...
November 28, 2014

Math typo
.... she walks 1 1/4 of an hour. Huh?
November 28, 2014

Physics
It only weighs about 270 N if 27 kg He is pulling with 454 N That is not right unless it is hooked to an anchor. It should probably be 270 kg for about 2700 N weight
November 28, 2014

Physics
Normal force on floor = m g - 454 sin 37 friction force = mu * normal force but friction force = 363 N you said so 363 = mu (27*9.8 - 454 sin 37)
November 28, 2014

Physics
ah, as happy as he ever got that is.
November 28, 2014

Physics
By the way I went to some pain to elaborate on this because a scientist named Edward Teller (Google him) asked me that very question in a slightly different manner when I was interviewing for a fellowship many years ago. I gave him the answer I just gave you and he was happy :)
November 28, 2014

Physics
It is very hard for a wave to change frequency. You have to store some of the waves somewhere if you do that because in the end the same number must enter one end of the box as come out the other. Think ocean waves coming into a beach, They slow down in the shallow water so ...
November 28, 2014

physics
Cut line, 2/3 and 1/3 Secure end of shorter line to tree. Reeve through block at car and secure to the hook on your second block which will be a traveling block Now secure the end of your longer line to the tree Run that line through the sheeve on the traveling block now look ...
November 28, 2014

Physics
(specific gravity of this oil*7 + 8)62.4 in pounds/ft^2 divide by 144 to get psi, pounds per square inch I do not know the ratio of this oil density to that of water
November 28, 2014

Calculus
How do we know h = 15 ? If we do not know h, then the solution is something that looks like a space needle :) L * w * h = 2160 if h = 15 L * w = 144 L = 144/w cost = c = 5(L*w) + 2 L*h + 2 w*h c = 5 L w + 2 w h + 2 L h if we know h = 15, then c = 5 L w + 30 w + 30 L c = 5*144...
November 28, 2014

Math
sin 63 = h/25
November 28, 2014

Alg !
http://www.mathsisfun.com/algebra/sequences-sums-arithmetic.html
November 28, 2014

whoops
1 = 1/24 r^3 r^3 = 24 r = 2 sqrt 3 again can not be both
November 28, 2014

math
a r^2 = 9 a so r = 3 ar = (1/24) a r^4 r = (1/24) r^3 24 = r^2 but r = 3, can not be 3 and sqrt 24 a r^3 is fourth term 27 a = ? 48 ? a = 48/27 ? I think you have this messed up.
November 28, 2014

English
yes
November 28, 2014

math
a ar^1 ar^2 ar^3 ----- ar^(n-1) ar^2 = 9a so a = 3 a r = (1/24) a r^4 r = (1/24) r^4 r^3 = 24 = 8*3 remember this so r = 2 *3^(1/3) fourth = a r^3 = 3 *24 = 72
November 28, 2014

calculus
a = -g = -9.8 m/s^2 The statement gives you the answer. v = integral a dt = -9.8 t + c at t = 0 v = Vi = 5 m/s so c = 5 v = -9.8 t + 5 h = integral v dt = 5 t -(9.8)/2 t^2 + cc when t = 0 h = Hi = 442 so cc = 442 h = 442 + 5 t - 4.9 t^2 (check your physics book :) at top, v = ...
November 28, 2014

physics, how to find the height
At max height all velocity is horizontal u = 26 but u = 65 cos Theta so Theta, the angle shot above horizontal = 66.4 deg so Vi = initial up speed = 65 sin Theta = 59.6 at top vertical speed = 0 so 0 = 59.6 - 9.8 t where t is rise time t = 6.08 seconds going up H = 0 + 59.6 t...
November 27, 2014

physics
Vi = 2.7 m/s h = 11 + 2.7 t = 4.9 t^2 0 = 11 + 2.7 t - 4.9 t^2 at ground 4.9 t^2 - 2.7 t - 11 = 0 t = [ 2.7 +/- sqt (2.7^2 +44*4.9) ]/9.8
November 27, 2014

Math
been there, done that http://www.jiskha.com/display.cgi?id=1417133335
November 27, 2014

physics
24 = (1/2)g t^2 48 = 9.8 t^2 t 2.21 seconds
November 27, 2014

algebra
.3 a + .8 b = .4 * 10 a + b = 10 .3 a + .8 b = 4 .8 a + .8 b = 8 ---------------- subtract -.5 a = - 4 a = 8 so b = 2
November 27, 2014

Pre-Calc.
LOL, but if two angles are 60 then so is the third and it is an equilateral triangle :) base = 24 12^2 + h^2 = 24^2 h^2 = -(3*4)^2 + (6 *4)^2 h^2 = 4^2 ( -9+36) = 4^2 (27) = 4^2*3^3 h = 4*3 * sqrt 3 h = 12 sqrt 3
November 27, 2014

physics
The mechanical energy of the system is the sum of kinetic and potential energy. In this ideal world it does not change with time. Since you found the maximum speed use (1/2) m v^2
November 27, 2014

math
a b c c = 2 a a + b + c = 14 a b 2a 3 a + b = 14 ones digit is even 1 b 2 ---> 3+b=14, b = 11 no 2 b 4 ----> 6 + b =14, b = 8 ok so 2 8 4
November 27, 2014

math
1 2 4 8 16 1 2^1 2^2 2^3 2^(n-1) a a2^1 a 2^2 .... geometric sequence with a = 1 r = 2 n = number of days 2^59 = area 2^x = 2^59/2 x = n-1 = 58 so 59 days which we could have said right off because if you cover the whole lake in 60 days then the day before you must have half ...
November 27, 2014

algebra 2
16 x^2 - 56 x = 0 x (16 x^2 - 56 ) = 0 x = 0 or x = 56/16
November 27, 2014

math
a ar^1 ar^2 ar^3 .... ar^(n-1) so a r^2 = 9 a a r^1 = (1/24)ar^4 ----------------------- ----------------------- so r = 3 a(3) = (1/24)a (3)^4 This is not possible. You have a typo.
November 27, 2014

Math
You are welcome.
November 27, 2014

Math
3/2 = L/b = 1.5/b 3 b = 3 b = 1
November 27, 2014

Physics
F = m a weight = m a a = -mg/m = - g in other words acceleration is down at -10 m/s^2 dv/dt = a = -10 so v = -10 t + c but at t = 0, v = +10 so c = 10 and v = -10 t + 10 now at the top, v = 0 0 = -10 t + 10 so at the top when t = 1 if v = -10 t + 10 then h = Hi + 10 t - 5 t^2 ...
November 27, 2014

math
I do not have a politically correct answer to your preamble question.
November 27, 2014

math
2 x + 3 y = 92 4 x - 7 y = 2 4 x + 6 y = 184 4 x - 7 y = 2 --------------------- 13 y = 182 y = 14 etc
November 27, 2014

physics
a quantity that has both magnitude and direction. for example you can measure the speed or magnitude of velocity of a car with a speedometer. However to specify the velocity vector you also need a compass. 20 km/hour is a scalar magnitude, speed 20 km/hour EAST is a vector.
November 27, 2014

physics, how to find the height
a = -g with g unknown at h = 0, Pe = 0 and Ke = (1/2)m Vi^2 = total energy at h = Htop , v = o and Pe = m g Htop = (1/2) m Vi^2 so Htop = Vi^2/2g at h = Htop/4 Pe = m g (Htop/4) = m Vi^2/8 total energy still = m Vi^2/2 so Ke = (3/4) (1/2)m Vi^2 so it still has (3/4) of initial...
November 26, 2014

U.S. History Help!!!!!!!
1 c I think (there were a lot of tories) 2 a 3 d
November 26, 2014

Math
.70 p = 72.09 p = 72.09/.7 = 102.99
November 26, 2014

Language Arts
I would pick B.
November 26, 2014

Statistics
http://davidmlane.com/hyperstat/z_table.html
November 26, 2014

six sigma
http://davidmlane.com/hyperstat/z_table.html
November 26, 2014

physics
vertical problem Vi = 2390 sin 49.6 v = Vi - 9.8 t at top v = 0 so t = Vi/9.8 at top that is half the trip hits ground at tg = Vi/4.9 Now the horizontal problem u = 2390 sin 49.6 range = u tg range = 2390 sin 49.6 * Vi/4.9 so range = 2390^2 sin 49.6 cos49.6 /4.9 = 575369 ...
November 26, 2014

math
9/30 = 3/10
November 26, 2014

Bus. Math
s - .55 s = 5.12 .45 s = 5.12 s = 11.38 check 5.12 + .55(11.38) = 11.38
November 26, 2014

math
18+3 = 20 + 1 = 21 27 + 4 = 30 + 1 = 31 practice by drawing the problem on a number line.
November 26, 2014

gen chem
1/L = 10^7 (1/49 - 1/81) 1/L = 10^7( .00806 ) = .806* 10^4 L = 1.24 * 10^-4 meters
November 26, 2014

MATHEMATICS
Go back and read: 5 .55 That is a but you asked for term 6 which is a r^5 5.55 * 1.44^5 about 34.4
November 26, 2014

Math
.25 x = 3 x = 300/25 = 12
November 26, 2014

Math
.2 x = 80 x = 80/.2 = 800/2 = 400
November 26, 2014

Chem
Temp = 37 + 273 = 310 K P V = n R T V = .1 R (310)/92,000 but R = 8.315 Pascals m^3/mol K V = .1 * 8.315 * 310 /92,000 meters^3
November 26, 2014

math
(1)hypotenuse = straight home sqrt(36+64) = 10 straight is 10 miles same way is 6+8 = 14 miles (2) hypotenuse of 3,4 5 right triangle is 5 5*6 = 30 plus enough for the knots :) (3)diagonal (hypotenuse) length is the longest sqrt (42^2 + 84^2) = 93.9, so no
November 26, 2014

Chem please help
You do not need the s on https http://www.boundless.com/biology/textbooks/boundless-biology-textbook/metabolism-6/potential-kinetic-free-and-activation-energy-69/free-energy-345-11482/
November 26, 2014

Chem please help
or better: https://www.boundless.com/biology/textbooks/boundless-biology-textbook/metabolism-6/potential-kinetic-free-and-activation-energy-69/free-energy-345-11482/
November 26, 2014

Chem please help
http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/helmholtz.html
November 26, 2014

Math--1 question
30 31 32 -- 33 -- 34 35 54 median clearly is 33 mean = sum /7 mode - no value occurs more than any other ranges from 30 to 54
November 26, 2014

Coordinate Geometry (Algebra 1)
First RS slope = (4 - -5) / (-8 - 4) = 9/-12 = -3/4 so it is y = -(3/4) x + b no need to find b, all we need is the slope -3/4 so slope of perpendicular = -1/m = +4/3 so 4/3 = (y-6) /( -3 - 0) 4/3 = (y-6)/-3 -4 = y-6 y = 2
November 26, 2014

MATHEMATICS
Been there, done that check below
November 26, 2014

MATHAMATICS
That is a but you asked for term 6 which is a r^5 5.55 * 1.44^5 about 34.4
November 26, 2014

MATHAMATICS
a ar ar^2 ar^3 etc a r^n-1 a r^4 = 24 a r^7 = 72 r^7/r^4 = 72/24 r^3 = 3 r = 3^(1/3) a 3^(4/3) = 24 a = 24 * 3^-(4/3) a = 5.55 r = 1.44 check a r^4 = 24.01 a r^7 = 72.04 ok
November 26, 2014

math!!
5^9
November 26, 2014

physics
initial momentum = 0 so final momentum = 0 0 = 80*1.5 + 120 * V V = - 120/120 = -1 meter/second
November 26, 2014

math
the first place on the right is either 0 or 1 times 2^0 which is one just as in base 10 the first place on the right is 0 1,2...9 or one of those numerals times 10^0 which is one the second place on the right is either 0 or 1 times 2^1 which is 2 just as in base 10 the second ...
November 26, 2014

math
1 * 2^0 = 1 0 * 2^1 = 0 1 * 2^2 = 4 1 * 2^3 = 8 so 13
November 26, 2014

math
1.25 L + .75 s = 109.75 L + s = 105 so s = (105-L) so 1.25 L + .75 (105-L) = 109.75
November 26, 2014

Physics
Force * distance/ time 85 * 9.8 * 2.5 Joules/second or Watts
November 25, 2014

math
7 * x^.5 * x^.5 = 7 * x^1 = 7 x
November 25, 2014

math
7 x
November 25, 2014

chemistry
H is enthalpy but I do physics, not chemistry.
November 25, 2014

chemistry
And I still think it is Physics :)
November 25, 2014

chemistry
(for example solids to gasses :)
November 25, 2014

chemistry
Increasing entropy is increasing disorder. look here http://chemistry.about.com/od/workedchemistryproblems/a/Entropy-Change-Example-Problem.htm note - more spread out --> more entropy
November 25, 2014

physics
yes
November 25, 2014

physics
350/353 = .991 seconds
November 25, 2014

physics
353 m/s
November 25, 2014

physics
http://hyperphysics.phy-astr.gsu.edu/hbase/sound/souspe.html
November 25, 2014

physics
No, you must look it up
November 25, 2014

physics
That sounds good. I did not look up the speed of sound at that temp.
November 25, 2014

physics
that is the frequency 1.3 kHz =1300 Hz period = 1/frequency
November 25, 2014

physics
You will have to look up the speed of sound in meters/s, somewhere around 350, at 35 C ,call it v distance = speed * time (a) t = 350/v (b) period = T = 1/f wavelength = speed * period lambda = v /1300
November 25, 2014

Science 1 easy question!!!!
Sure, fine. Of course I do not know the exact words your text used but suspect you got them there.
November 25, 2014

Science 1 easy question!!!!
yes, that will do.
November 25, 2014

math
pi (Rout^2 - Rin^2) = 8.68 In other words just hollow out the shaft.
November 25, 2014

Science 1 easy question!!!!
yes, those are ions, not sharing, giving and grabbing
November 25, 2014

math
https://www.mathsisfun.com/definitions/triangular-prism.html
November 25, 2014

Physics help
D is rather orderly and counter to increasing entropy by throwing them all around the room.
November 25, 2014

Maths
AB up y axis from (0,0) s to (0,s) then BC right s (s,s) then CD down s to (s,0) then DA left to (0,0) O at (x,y) a = -x i - y j b = -x i + (s-y) j c = (s-x)i (s-y) j unknown d = (s-x)i - y j c + a - b = (s-x)i +(s-y)j-y j -(s-y)j = (s-x)i - y j (Caramba) so I get d = c + a - b
November 25, 2014

finance
for normal curve calculations I use: http://davidmlane.com/hyperstat/z_table.html
November 25, 2014

Chemistry
100 * 3.46 / 3.67
November 25, 2014

Chemistry
http://www.jiskha.com/display.cgi?id=1416948226
November 25, 2014

Chemistry
did that a few minutes ago
November 25, 2014

Thermodynamics
dQ/T is negative for part of the cycle and positive for another. Of course if you include the surroundings overall entropy shows its usual tendency to increase :)
November 25, 2014

Chemistry
2Zn + O2 ---> 2 ZnO Zn = 65 O = 16 ZnO = 81 g/mol 2.8 g / 81 g/mol = .0346 mol ZnO half as many O2 mols = .0173 mol O2 .0173 * 32 g/mol = .553 mol O2
November 25, 2014

programming
n = 0 1 read x n = n + 1 print x If n > 1, go down to 2 small = x large = x 2 If x</= small, then small = x If x>/= large, then large = x If n < 12 , go back up to 1 Print small Print large end
November 25, 2014

physics
P V = n R T so P1 V1 = P2 V2 2374 V1 = 14.7 * 194
November 25, 2014

Maths
You are welcome.
November 25, 2014

Maths
5/6 = 175/g 5 g = 6 * 175 g = 6 * 175 / 5
November 25, 2014

finnce100
Maybe sell calls at a strike above the present price. Use that income to buy puts at a strike price lower than present price. That limits your future gains to the amount between present and call strike but gives you protection against a catastrophic fall.
November 25, 2014

math
-2 p + 2 q
November 25, 2014

Chemistry
{OH][H] = 10^-14 [H] = 10^-14/10^-3 = 10^-14 * 10^3 = 10^-11 strong base
November 25, 2014

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