Friday
February 12, 2016

Posts by damon

Total # Posts: 25,219

MATH>:(
space 1, any of 7 space 2, any of 6 space 3, any of 5 etc 7! = 7*6*5*4*3*2*1 = 5040
February 11, 2016

Pre-Calc
(x+a)(x+a) x = -a or x = -a :) -a,-a (-a)^2 + 2a(-a) + a^2 a^2 - 2 a^2 + a^2 = 0 would you believe?
February 11, 2016

Math
height = 4 cm length = width = x-8 (x-8)(x-8)4 = 324 x^2 -16 x + 64 = 81 x^2 - 16 x - 17 = 0 (x-17)(x+1) = 0 well it is not -1 so x = 17 17 by 17
February 11, 2016

been there, done that
did that above
February 11, 2016

Linear Algebra
Here you go: http://en.wikipedia.org/wiki/Linear_algebra
February 11, 2016

Linear Algebra
By the way , that is algebra, and it is linear, but it is not "linear algebra" Google "linear algebra " :)
February 11, 2016

Linear Algebra
(Y2-Y1)/(X2-X1) = (1+3) /(1+2) = 4/3
February 11, 2016

Linear Algebra 8; Slope-Intercept Form
Now that was not even linear, never mind linear algebra LOL
February 11, 2016

Linear Algebra 8; Slope-Intercept Form
7^2 + x^2 = 11^2 49 + x^2 = 121 x^2 = 72 = 36 * 2 x = 6 sqrt 2 = 8.48528 which is around 8.5
February 11, 2016

General physics
x direction Fx = 2.8 + 4 = 6.8 Fy = -3.5 - 11.5 = - 15 Ax = 6.8/4.6 Ay = -15/4.6 |A| = sqrt (Ax^2 + Ay^2)
February 10, 2016

Math
well, it looks like y depends on x so if x = 6 then y = 60 - 3
February 10, 2016

algebra
Anyway, my way is more fun !
February 10, 2016

algebra
I GET x^2 + 6 x -7 facor that (x+7)(x-1) so -7 and 1 the end finally
February 10, 2016

algebra
I get (x-2)(x^3 + 8 x^2 + 5 x - 14) now 14 is either 14 and 1 or 7 and 2 2 does not work this time :( try -2 -8 + 32 -10 - 14 =-24+24 = 0 CARAMBA !!! X = -2 IS A SOLUTION SO (x+2)(x-2) so far divide x^3+8x^2+5x-14 by (x+2)
February 10, 2016

algebra
well, 28 has to have factors 2 14 4 7 lets try 2 and -2 16 + 48 -44 - 48 +28 lo and behold = 0 so x = 2 is a solution and (x-2) is a factor so divide that mess by (x-2) I get with long division (to be continued :)
February 10, 2016

alebra
This is a circle x^2 + 8 x + 16 + y^2 -8y +16 = 49+32 = 81 = 9^2 (x+4)^2 + (y-4)^2 = 9^2 center at x = -4 , y = +4 , radius 9 sketch it Now do the problem when x = 0 y^2 - 8 y - 49 = 0 y = [ 8 +/- sqrt (64+196) ]/2 y = 4 (of course) +/- 6.32 when y = 0 x^2 + 8 x - 49 = 0 x...
February 10, 2016

Algebra 2
LOL 90 + 45 + other angle = 180 so other angle = 45 In other words we know from the start that it is an isoceles right triangle. sides are 8 hypotenuse is 8 sqrt 2 because 1^2 + 1^2 = 2^2 :)
February 10, 2016

Math
A and A-2 A + A - 2 = 24 2 A = 26 A = 13 B = 11
February 10, 2016

Physics
I asks where the potential is zero, not necessarily where the force is zero You can add the potential due to the two charges on the x axis V = k Q/R1 = k Q1 /|x-xq| forget k and the 10^-6 because they are the same for both and we are looking for zero I will do the - 2 first -2...
February 9, 2016

Spelling
Now Rahul, do you get that (a^2-b^2) = (a+b)(a-b)
February 9, 2016

Spelling
ROTFL How can you make a cohesive sentence using the word cohesive? IS one :) I am not sure about the Elmer's sentence, would have used "adhesive". However the cohesive group works.
February 9, 2016

Algebra
what you are missing is a rule to remember a^2-b^2 = (a+b)(a-b)
February 9, 2016

Algebra
(x^2-a^2)/(x-a) = (x-a)(x+a) /(x-a) = (x+a)
February 9, 2016

Algebra
x^2 - a^2 = x^2 - a^2 (x-a)^2 = x^2 - 2 a x + a^2 quite a different animal
February 9, 2016

math
-4^.000001 = -1.000001386 :) it really means - (4)^0
February 9, 2016

physics
Tension = T T sin 20 = weight = m g so T = m g/sin 20 = 28.7 * m if g = 9.81 m v^2/R = T cos 20 = 28.7 m (.94) so v^2/R = 27 v^2 = 27 R R = 1.5 cos 20 = 1.41 meter so v^2 = 27(1.41) v = 6.17 m/s circumference = 2 pi R = 8.86 meters time around = 8.86 meters/6.17 m/s = 1.44 ...
February 9, 2016

Math
term n = 32 (1.5)^(n-1) when n = 1 term 1 = 32 (1.5)^(1-1) = 32(1.5)^0 but anything^0 = 1 so first term is 32 when n-1 = 0 32 48 72 108 162 243 364.5 546.75 etc
February 9, 2016

Math
48 - 32 = 16 = d 108 - 72 = 36 = d d is NOT CONSTANT SO NOT arithmetic !!!!!!! but 48/32 = 1.5 = r 108/72 = 1.5 = r SUCCESS ! r, the ratio, is 1.5, GEOMETRIC
February 9, 2016

Physics
m g h = 981 Joules 245 Joules is lost heating the pavement 981 - 245 = 736 Joules is left at the bottom That 736 Joules is all Kinetic Energy now because m g h = m g * 0 = 0 245 Joules was lost. I do not know the time so can not tell you the rate of energy loss (power) ...
February 9, 2016

physics
E dot A = 3640 * .166 * .72 = yes, 435 N m^2 /C If the plane is turned 90 degrees, none of the E field goes through it. E dot A = 0 The answer is ZERO
February 9, 2016

Algebra
Huh? They are all the same.
February 9, 2016

math, ratios
the number of pairs of shoes to number of shoes is 1/2 I can trade 29 dofrangles for every 30 fringbats. These are adjacent country currencies on the island of Qfrink. In fact I can get one dollar for every 29 dofrangles and one dollar for every 30 fringbats. there are 52 ...
February 9, 2016

Chemistry
Well, you can find the electric field E due to charge 1 at charge 2, then multiply that field by charge 2 to find the repulsive force (note, same sign charge repels, different signs attract) HOWEVER, normally you use Coulombs Law F = k Q1 Q2 / r^2 ( Google "Coulomb's ...
February 9, 2016

Chemistry
I guess that is CuC2 hydrated with x H2O CuC2 = 63.5 + 24 = 87.5 grams/mol so 1.6045 grams * 1 mol/87.5 grams = .0183 mol of CuC2 H2O = 18 grams/mol we have how many mols of H2O? 1.9045 - 1.6045 = 0.3 grams H2O so 0.3 / 18 = .01667 mol H2O looks like about as many mols of H2O ...
February 9, 2016

pysics
force times distance in the direction of the force = 20 N * 1 meter = 20 Joules
February 9, 2016

physics
omega = sqrt (k/m) = sqrt (12.6/.0107) = 34.3 radians/s x = .378 cos (omega t) v = -.378(34.3) sin (omega t) when x = .378/2 cos(omega t) = .5 then omega t = 60 degrees = pi/3 radians then sin (omega t) = .866 (I am ignoring signs here, we need speed not velocity) v = .378 * ...
February 9, 2016

Physics
positive v from 0 to 2 negative v from 2 to 5 positive v from 5 to infinity parabola holds water, crosses below x axis between 2 and 5 vertex at t = 3.5
February 9, 2016

Physics
ans part 3 is from - 30 to + 2 = +32
February 9, 2016

Physics no part 4
part 4 use absolute value of distance is 52 + 20 = 72
February 9, 2016

Physics
I assume that we do not do negative time so v is positive for 0<t<2 and for t >5 when t = 0, x = -30 when t = 2, x = 22 when t = 4, x = 2 so 28 from 0 to 4 (part 3)agree part 4 +52-20 = 32
February 9, 2016

Physics
dx/dt = 6 t^2 - 42 t + 60 = 6 (t^2 - 7 t + 10) = 6 (t-2)(t-5) negative from 2 to 5 (Not 3 to 5)
February 9, 2016

Calculus
c = cups/day p = pennies/cup dc/dp = -2/5 so c = -(2/5) p + constant when p = 50, c = 40 so 40 = -2*50/5 + constant constant = 60 and c = -(2/5) p + 60 now you can make that p = 5n if you choose where n is an integer number of nickels c = -2 n + 60
February 8, 2016

physics
Now I did the grasshopper, same deal
February 8, 2016

physics
h = Vi t - 4.9 t^2 .587 = Vi t - .5*9.81 t^2 but t at top is Vi/9.81 where 0 = Vi - g t .587 = Vi^2/9.81 - .5 * 9.81 (Vi^2/9.81^2) .587 = .5 * Vi^2/9.81 Vi = 3.39 m/s vertical up Vi = speed * sin 58 so speed = 4.00 m/s part a u = 4.00 cos 58 = 2.12 m/s time in air = 2 * rise ...
February 8, 2016

Math
out of n, n-6 were gotten right so let's find n-6 Jack alone got 40 -32 = 8 Jill alone got 50-32 = 18 so in total alone they got 26 plus they got 32 together 26 + 32 = 58 right total plus the 6 wrong = 64
February 8, 2016

maths
every year multiply value by 0.90 1 year= 20,000 * .9 2 years 20,000 * .9^2 3 years 20,000 * .9^3 so part (c) n years 20,000 * .9^n It is like reverse compound interest, it will not go down 2,000 every year, but only 10% of its MOST RECENT value every year so 2 years 20,000...
February 8, 2016

History
Hey, that is pretty good. I am not a fan of his mother though.
February 8, 2016

physics
v at 10 m/s at t = 0 a = (final velocity-initial velocity)/time = (20 - 10)/5 = 2 m/s^2 so from (0,10) slope up = 2 m/s^2 to (5,20) from (5,20) to (25,20) horizontal from (25,20) to (35, 0 ) straight slope down (slope = -2)
February 8, 2016

physics
a = (final velocity -initial velocity)/time a = 49/16 m/s^2 weight = m g + m(49/16)
February 8, 2016

maths
looks like arithmetic sequence a = 3 d = 2 however sum of what terms?
February 8, 2016

Physics
now do A = F/m
February 8, 2016

Physics
Its acceleration will be in the direction of the net force Force horizontal component= Fh = 6.6*10^6 cos 47.5 Force vertical component = Fv = 6.6*10^6 sin 47.5 - 4.5*10^5*9.81 so Fh = 4.46*10^6 N Fv = 2.19*10^6 N F = sqrt(Fh^2+Fv^2) = 4.97*10^6 N tan A = Fv/Fh = 2.19/4.46
February 8, 2016

Science
eg: http://en.wikipedia.org/wiki/Lunar_mare
February 8, 2016

Science
1 a yes 2 b yes 3 a no b 4 c no d usually moon blocks sun light 5 a no c 6 d no b 7 a no c 8 b no a it all hits the other side 9 d no b 10 Google !!!! Hey - get yourself a light and a tennis ball and a soccer ball !
February 8, 2016

Math Questions
You are welcome.
February 8, 2016

Math Questions
2(9/3) = 2(3) = 6 yes 1 (18/6) = 1(3) = 3 yes 4 (10/5) = 4(2) = 8 yes
February 8, 2016

Math Questions
7(16/8) = 7(2) = 14 yes 6 (10/10) = 6(1) = 6 yes
February 8, 2016

Math
9.25% monthly .095/12 = .0079167 so every month multiply by 1.0079167 y = 1,000 (1.0079167)^(12x) now just activate your calculator :)
February 8, 2016

Maths
f(x,y) = 2 (x^2 + xy + 3 y + y^2) How could that be less than 0?
February 8, 2016

typos
Increases ?? from 15 m/s to 6 m/s ??? anyway a = (final velocity - initial velocity) / time d = Vi t + (1/2) a t^2 = 15 (20) + (1/2) a (400)
February 8, 2016

maths
a + (n-1) d second is a + d = 15 fifth is a + 4 d = 24 so a = 15 - d and (15-d) + 4 d = 24 3 d = 9 d = 3 then a = 12 so term n is 12 + (n-1)3
February 8, 2016

Math Please help me and fast
yes if you had 5 x = 0 for example, that would work for any old x and you would have infinite number of solutions. This is the opposite case.
February 8, 2016

Math Please help me and fast
0 x = 2 x = 2/0 undefined 4 y = 12 y = 3 b - 9 > 20 add 9 to both sides b > 29
February 8, 2016

Math
1. yes y = 100 (1/2)^(t/3) 2. looks good, divide by 2 every three days 3. I can not very well show you a graph maybe google graph exponential or graph A * B^-(kt) 4. 100 /(1/2)^3 = 100/(1/8) = 800 so yes but do not understand how you did it
February 8, 2016

Algebra
P = K D^2
February 8, 2016

Physics
F = k *stretch for each each supports 7.35 * 9.81/3 = 24 N 24 = k (.21) k = 115 N/m agree except you use 9.8 for g I suspect K = 3 k from part a = 343 omega = 2 pi f = sqrt(K/m) = 6.83 radians/s f = omega/2pi = 1.09 Hz T = 1/f = .919 seconds agree V = A omega sin (omega t) max...
February 8, 2016

social studies
My guess: The promises England had made to Palestinians.
February 8, 2016

Probability
Well, I guess about half of them 99,000 + 00,000 ? = 100,000 so I suppose about 50,000
February 8, 2016

Physics
a = (final velocity-initial velocity) / time a = (0 - Vi)/1.7 so a = -Vi/1.7 d = Vi t + (1/2) a t^2 50.7=Vi(1.7) -(1/2)(Vi/1.7)(1.7)^2 50.7 = (1/2)(1.7)Vi Vi = 59.6 m/s then a = - Vi/1.7 = -35.1 m/s^2 so F = m a = 13(-35.1) = - 456 N
February 8, 2016

physics
F1 horizontal T at 40 degrees from Vertical T cos 40 = m g T = 10 * 9.81 / cos 40 = 128 N F1 = T sin 40 = 128 sin 40 = 82.3 N
February 7, 2016

Physics
F on glider from spring = -kx beginning x = .1 meter potential energy in spring = kd^2/2 where d is extension = 5 d^2/2 = 2.5 d^2 = 2.5 (.1-x)^2 the potential energy at start = 2.5(.1)^2 = .025 Joules total the kinetic energy = (1/2)mv^2 = .1 (.2)^2 = .004 Joules so .025 = ....
February 7, 2016

physics
F = 1050 - 916 = 134 N UP a = F/m = 134/93.5 = 1.43 m/s^2 UP in other words his speed down is slowing
February 7, 2016

physics
I guess you mean maximum height of 100 m Vertical problem: Vi = 59 sin A v = Vi - 9.81 t at top v = 0 0 = Vi - 9.81 t so t = 59 sin A /9.81 at top 100 = Vi t - (9.81/2) t^2 100 = (59 sinA)^2/ 9.81 -(9.81/2) (59 sin a)^2/9.81^2 100 = (1/2)(59 sin A)^2/9.81 980*2 = (59 sin A)^2 ...
February 7, 2016

physics
We just need to do the vertical part of the problem. I assume it hit the ground where H = 0 Vi = 15 sin 35 = 8.6 m/s up H = Hi + Vi t - 4.9 t^2 0 = Hi + 8.6 (2.7) - 4.9 (2.7)^2 Hi = 12.5 meters
February 7, 2016

physics
You are welcome. I am sorry; I have no schedule (retired and doing a lot of other stuff).
February 7, 2016

physics
and tan angle = 22.2/16
February 7, 2016

physics
typo sqrt (22.2^2 + 16^2)
February 7, 2016

but the horizontal speed?
25 = 4.9 t^2 t = 2.26 seconds, yes v = Vi - 9.81 t v = -9.81(2.26) = -22.2 BUT WHAT ABOUT u ? 16 m/s horizontal speed = sqrt (22.2^2+16)^2 tan angle below horizontal = 16/22.2
February 7, 2016

math
n * (n-1) = 90 the rest cancels agree n^2 - n = 90 n^2 - n - 90 = 0 agree n = 10 or n = -9 agree 10 * 9 [ (n-2)! / (n-2)! ] = 90 for me all right
February 7, 2016

math
2 W + 2 (2 W + 3) = 66 6 W + 6 = 66 6 W = 60 etc
February 7, 2016

algebra
term 2 = a r term 4 = a r^3 term 5 = a r^4 term 1 = 1 term 3 = a r^2 ---------------------- ar (ar^3) = 2 (a r^4) a^2 r^4 = 2 a r^4 2 a = a^2 a^2 - 2 a = 0 a = 0 (won't work) or a = 2 now we need r I assume you mean the sum of the first 4 is 80 a + ar + ar^2 + a r^3 = 80 1...
February 7, 2016

Maths, Problem solving
x + x/4 +(x-90) = 180 2.25 x = 270 x = 120
February 7, 2016

Statistic
.75 and .83 .83 - .75 = .08 .08/.05 = 1.6 = z assuming your .05 is sigma and distribution normal http://davidmlane.com/hyperstat/z_table.html I get probability of .08 or above is about .05 I think the extra schooling helped
February 7, 2016

physics
That is really impossible to calculate. There is a change of momentum during the collision and force = change of momentum / duration of actual collision. That would be a fraction of a second but how long depends on the crushing characteristics of the body.
February 7, 2016

maths
90/90 - 28/90 = 62/90 = 31/45
February 7, 2016

physics (mechanics)
a = (20-15)/10 = 0.5 m/s^2 F = m a F = 1000 (0.5) + 270 F = 500 + 270 F = 770 N
February 7, 2016

math
combined speed = 110 110 mi/h * t = 660 t = 6 yes
February 6, 2016

Math
d = 4 q 10 d + 25 q = 390 10 (4q) + 25 q = 390 65 q = 390 q = 6 etc Your error is here: 0.40q+0.25q=3.90 then you said 65q=3.90 no 0.65 g = 3.90 3.90/0.65 = 6 not .06
February 6, 2016

pysics
Q = C m (T2-T1) = 400 (.5 kg) (116-16) note difference in deg K is the same as difference in deg C = 20,000 Joules
February 6, 2016

Math
34.375 / .125 = 275 I divided I do it the science way, multiply so units cancel you can do it by ratios .125 in/1 ft = 34.375 in / x ft .125 x = 34.375 x = 34.375 / .125
February 6, 2016

Math
34.375 in (1 ft/.125 in) = 275 ft
February 6, 2016

Math
That name game is just part of trying to hopelessly confuse me.
February 6, 2016

Math
LOL, talk about trying to confuse me ! If those are corresponding sides in two triangles and A is 4 times X then B is 4 times Y and m = 10/4 = 2.5 and C is 4 times Z and n = 16/4 = 4
February 6, 2016

Math
not without knowing the angles
February 6, 2016

Physics 30
Hey, just use Coulomb's Law F = k Q1 Q2 / d^2 if like charges, repel if opposite signs, attract see: http://en.wikipedia.org/wiki/Coulomb's_law
February 6, 2016

physics & math
sqrt ( 2*1.6*10) = 4 sqrt 2 = 5.66 m/s
February 6, 2016

typos
You mean g = - 32 ft/s^2 so h = Hi + Vi t + (1/2)a t^2 h = 105 - 9 t - 16 t^2 at ground: 0 = 105 - 9 t - 16 t^2 or 16 t^2 + 9 t - 105 = 0 t = [ -9 +/- sqrt(81+6720)]/32 t = [-9 +/- 82.5 ]/32 use positive time 2.30 seconds
February 5, 2016

Physics
V= i R 2 = .1 R and 2 = 5 R
February 4, 2016

Physics help
well electrostatic force causes hair to stand on end and gravity keeps the planets in orbit by the way
February 4, 2016

Physics PLEASE PLEASE HELP! CONFUSED
do vertical and horizontal problems separately Vertical Just plain fall, no initial velocity up or down so a) 10 = (1/2)(9.81) t^2 b) use that t to find out how far away he landed d = u t = 1.2 t c) vertical v = g t = 9.81 t horizontal u = 1.2 speed = sqrt (u^2+v^2) direction ...
February 3, 2016

  1. Pages:
  2. 1
  3. 2
  4. 3
  5. 4
  6. 5
  7. 6
  8. 7
  9. 8
  10. 9
  11. 10
  12. 11
  13. 12
  14. 13
  15. 14
  16. 15
  17. Next>>