Tuesday
August 30, 2016

Posts by Damon

Total # Posts: 26,839

simultaneous equation
x^2+2xy-8y^2=0 (x+4y)(x-2y) = 0 so two routes to follow x = 2 y and x = -4y now the first one with x = 2 y 4 y^2 + y^2 - 4 y^2 = 21 y = +21 or - 21 then x = 42 or -42 so (42,21) (-42,-21) now the first one with x = -4y I will leave that for you
April 8, 2016

physics- help me please
pressure is weight per unit area the area at the bottom of the glass does not change however the mass of Hg is 13 times as much as that or the water therefore the pressure will be 13 times as big as P Hey, imagine the experiment !
April 8, 2016

physics- help me please
please look up the density of each. copper lead uranium then multiply by volume copper mass = copper density * 4 lead mass = lead density * 4 uranium mass = uranium density* 2 then list them in order
April 8, 2016

PE
You are welcome.
April 8, 2016

PE
http://www.jiskha.com/display.cgi?id=1460138784#1460138784.1460140028
April 8, 2016

PE
Look down to where I answered this.
April 8, 2016

PE
been there, did that scroll down
April 8, 2016

Math
Yikes, I did this a few minutes ago as well. 2
April 8, 2016

Math
How on earth would a bunch of retired teachers have the slightest idea what book you have or even what country you live in ?
April 8, 2016

Math
OIC
April 8, 2016

Math
The school? No way !!!
April 8, 2016

Math
v = pi r^2 h = pi (16)8 = 402 in^3 just two is 804 in^3
April 8, 2016

P.E.
2. disagree - http://www.google.com/search?q=central+nervous+system+components&ie=utf-8&oe=utf-8 3. agree 4. agree 5. agree
April 8, 2016

c = 100 + 2 n
Just in case you gave up :)
April 8, 2016

ATTENTION TEACHERS AND STUDENTS
c = f + n v or cost = fixed + variable * number that is a straight line with slope v and c intercept f 1100 = f + (500) v 1400 = f + (650) v --subtract---- ------------------- -300 = -150 v v = 2 then 100 = f so c = 100 + 2 n if n = 1000 c = 100 + 2000 = 2100
April 8, 2016

Elementary education
inside radius = 1 inch outside radius = 1.0625 inch volume = 1.25 (pi)(1.0625^2-1) = .5062 in^3 mass = 6 * .5062 = 3.04 oz
April 8, 2016

Science
.75 * 2.5 * 166
April 8, 2016

Math
vol of half sphere = (1/2)(4/3)pi r^3 vol of cone = (1/3)(5)(pi r^2) where r = 1.5
April 8, 2016

Algebra 1-HELP!
if x = 4 y = 6(4) - 1 y = 24 - 1 y = 23
April 8, 2016

Math
Yes, you are correct
April 8, 2016

algebra
(x^2-1) ------- (x+1) (x+1)(x-1) ----------- (x+1) = x-1
April 8, 2016

Physics
Oh all right I will do one more before getting grandkids up for school. dr/dt = (3.2+3.6t)i + (1.7-4.8t)j d^2r/dt^2 = 3.6 i - 4.8 j which is the acceleration, so what else is new? |a| = sqrt(3.6^2 + 4.8^2) tan angle north of east = -4.8/3.6 so angle South of East = 53.1 deg
April 8, 2016

Physics
oh well original velocity = 2.1 i + 0 j final velocity = Vx i + Vy j sqrt (Vx^2 + Vy^2) = 6.3 so Vx^2 + Vy^2 = 39.7 (Vx - 2.1)/3 = Ax (Vy - 0)/3 = Ay so Ay = Vy/3 Ax^2 + Ay^2 = 1.4^2 = 1.96 so three equations Ax^2 + Vy^2/9 = 1.96 Vx^2+Vy^2 = 39.7 Ax = (Vx - 2.1)/3
April 8, 2016

chemistry
4 mols HCl = 4 * (1+35.5) = 146 grams of HCl per liter so either mix a liter that way and pour out .2 liter or put .2*146 = 29.2 grams of HCl in .2 liter of water Of course that is easier said than done because how do you get 29.2 grams of the acid HCl ? It is not a solid that...
April 8, 2016

Physics
how long do you take? 90 = 8 t t = 11.25 seconds 8 = 1.20 v v = 6.67 m/s so 90 = 6.67 t t = 13.5 s so you should start 13.50 - 11.25 = 2.25 seconds after him
April 8, 2016

Physics
you went 15/60 * 13 = 3.25 miles in first 13 min so 26 - 3.25 = 22.75 miles left and 34 - 13 = 21 minutes left which is 21/60 = .35 hours so 22.75 miles/.35 hours = 65 mph
April 8, 2016

math
+ 24 * 20 = 2 * 240 = 480
April 8, 2016

sorry, multiply by g
need weight/area, not mass /area 600 * 9.81 = 5886 Pascals
April 8, 2016

science
That little piece of wood does NOT weigh 900 kg (maybe your car does) I think you mean 0.900 kg or 900 grams make its contact with the table as small as possible while not tipping over (standing on end) so area touching table is .05 * .03 = .0015 m^2 so p = force/area = 0.9/....
April 8, 2016

Physics
h = 40.2 + Vi t - 4.9 t^2 at ground h = 0 4.9 t^2 - Vi t - 40.2 = 0 but t = 4 so solve for Vi
April 8, 2016

physics
x = sin (2pi*741t) y = sin (2pi*715t) x+y= sin (2pi*741t)+sin(2pi*715t) but sin a + sin b= 2 sin.5(a+b)cos.5(a-b) so x+y =2 [sin average] cos half difference every max of the cosine, either + or - is a big noise so what you hear if they are close is the average frequency times...
April 8, 2016

physics
you hear the difference frequency 8 = 3580 - f f = 3472 original 12 = 3580 -f f = 3568 final good, the frequency went down when I loosened the string so 3568 Hz WHAT if I wrote the difference the other way (all I know is the absolute value) 8 = f - 3580 f = 3588 12 = f - 3580 ...
April 8, 2016

Physics
4.8 = u t what is t, the time airborne? 2 = 4.9 t^2 so t = sqrt(.408) = .639 second so u = 4.8/.639 = 7.51 m/s
April 8, 2016

maths help me urgently!!!!!!
i^2 = -1 1 - 2(-1) = 3 so this is 3/i multiply top and bottom by i 3 i/-1 or -3i
April 7, 2016

physics
omega = w = 2 pi f = sqrt(k/m) w = sqrt (222/.58) = 19.56 radians/sso x = .0335 sin 19.56 t v = .0335(19.56) cos 19.56 t a = -.0335(19.56)^2 sin 19.56 t = -19.56^2 x max v when cos 19.56 t = 1 and x = 0 so all energy is kinetic max v = .655 m/s (1/2) m v^2 = .125 J agree with ...
April 7, 2016

Physics
Initial momentum 390*20 - 500*8 = 3800 , x direction Final momentum = (390 + 500)v = 890 v , x direction But we all know from the first law deduced by Isaac Newton that since there are no external forces on this system in the x direction there will be no change in x momentum. ...
April 7, 2016

Physics
22*13.8 - 188 v = 0 v = 1.61 m/s
April 7, 2016

maths
23/3 = 7 2/3 so 8
April 7, 2016

maths
one man takes (6hr/7holes)5 men = 30/7 man hr per hole so 15/7 for half a hole
April 7, 2016

maths
I needed a common multiple of 2 and 3 that is 6 we are not doing fractions here, just integers
April 7, 2016

maths
a b c d d = 2 a b = 2 c a+d = 2 c ---------------------- a = 2 c - d = 2 c - 2 a so 3 a = 2 c hmmmm if c is 1, nope need common multiple for integer like 3 a = 6 2 c = 6 looks like a = 2 and c = 3 so far: 2 b 3 d but d = 2 a 2 b 3 4 b = 2 c so 2 6 3 4 2634
April 7, 2016

calculus
v = 5 t^-.5 = 5/sqrt(t) a = dv/dt = -2.5 t^-2.5 x = (5/.5)t^.5+c = 10 t^.5 + c 11 = 10 (1)^.5 + c c = 1 so x = 10 sqrt(t) + 1
April 7, 2016

calculus
a = -9.8 v = Vi - 9.8 t h = Hi + Vi t +(1/2) a t^2 h = 2300 + 0 t - 4.9 t^2 = 2300 - 4.9 t^2
April 7, 2016

calculus
v = vi - a t 0 = 7 - 9.8 t t = 7/9.8 at top when v = 0 h = 3 + 7 t - 4.9 t^2
April 7, 2016

physics
frequency proportional to sqrt(g/L) g proportional to mass of planet and 1/r^2 g planet = g earth * 1.75/6.25 = .28 sqrt gplanet = sqrt gearth =.529 so frequency is .529 tht on earth period = 1/f so 1.6/.529 = 3.02 seconds
April 7, 2016

calculus
d^2y/dx^2 = x^2 dy/dx = (1/3)x^3 + c 8 = 0 + c so c = 8 or dy/dx = (1/3)x^3 + 8 y = (1/12)x^4 + 8 x + k 8 = 0 + k so k = 8 y = (1/12)x^4 + 8 x + 8
April 7, 2016

Pre cal
b = 12 / sin 55
April 7, 2016

Math
He ran more last week If he ran 6 miles last week then he ran 5 miles this week the 25 2/3 is just noise on the circuit all that matters is the 5/6
April 7, 2016

Math
Now that is quite enough ! 5/6 is LESS than ONE
April 7, 2016

physics
x = A sin 2 pi f t x = A sin 12.9 t v = dx/dt = 12.9 A cos 12.9 t v = 1.9 = 12.9 A cos 0 = 12.9 A A = 1.90/12.9 = .147 meter
April 7, 2016

English
A traditional African marriage is advantageous for the man but not for the woman.
April 7, 2016

Physics - urgent
http://www.physicsclassroom.com/class/sound/Lesson-5/Closed-End-Air-Columns remember period T = wavelength/speed and f = 1/T = 350/wavelength here the lowest frequency is when .14 meter = half a wavelength so wavelength = .28 meter lowest f = 350/.28
April 7, 2016

Pre cal
49 + 16 = 65 so sqrt 65 which is about 8.062257748
April 7, 2016

Science
I did not bother to Google but your answers look correct to me.
April 7, 2016

Physics
The center of mass of the system continues at rest because there are no external forces on the system. cg at 0 forever m girl * distance from 0 = m plank * distance from 0 center of plank moves 3 to right if girl now 2 meters from CG of system to left 3*12.6 = 2 m m = 3 * 6.3...
April 7, 2016

Physics
I assume a short circuit so total voltage is 0 V = L di/dt + iR = 0 let i = I e^kt then when t =0, i = I di/dt = I k e^kt = k i V = L I k e^kt + I e^kt R = 0 L k + R = 0 k = -R/L but I bet you knew that so k = -130/50*10^-3 = -2.6*10^3 I = 12 so i = 12 e^-2.6*10^3 t 4.8/12 = ....
April 7, 2016

Physics
frequency is proportional to square root of tension f *sqrt (25) = 5 f
April 7, 2016

Math
it will be 1/8 times as large so small
April 7, 2016

Math
Evie, all your questions are the same if the numerator is bigger than the denominator, the fraction is bigger than one 4/3 is bigger than one so MORE
April 7, 2016

math
30 ft (1 m/5280 ft) = .00568 mile v = .00568 /T in hours T in hours = .00568 /v T in seconds = 3600*.00568/v = 20.45/v clicks/second = 1/T = v/20.45 so v = 20.45 * clicks/second 1 click/second --> 20.45 mph 2 clicks/second -->41 mph v = 20.45 * clicks/second = clicks/20....
April 7, 2016

Math
2/5 is less than 5/5
April 7, 2016

Math
(5/4)w * w = 180
April 7, 2016

science
total y momentum = 0 m * 1.5 sin 30 = m v sin T so v sin T = 0.75 total x momentum = 2 m 2 m = 1.5 m cos 30 + m v cos T v cos T = .7 v sin T/v cosT = tan T = .75/.7 T = 47 degrees v = .7/cos 47
April 7, 2016

Math
L = 14 w/13 (14 w/13)(w) = 4800 w^2 = 13 (4800/14) w = 66.76
April 7, 2016

English
yes
April 7, 2016

Physics 1
potential energy loss = m g h = 3.08 * 9.8 * 1.27 = kinetic energy gain = (1/2) (1.95)v^2 + (1/2)I (v/r)^2 so what is v at the end of this experiment? find acceleration 1.27 = (1/2)a t^2 1.27 = (1/2)a (.83)^2 so a = 3.69 m/s^2 and v = a t = 3.69(.83) = 3.06 m/s at the end...
April 6, 2016

i need help plz
You, anyone, can copy a bit of it for just about any purpose - parody, comment, review, .... whatever
April 6, 2016

slope
well, check it and see.
April 6, 2016

slope
well, we know it is y = -4 x + b so all we need is b 5 = -4(9) + b 5 = -36 + b b = 41 so y = -4 x + 41
April 6, 2016

History
It stood officially for slave stealer, but abolitionists called it "slave savior".
April 6, 2016

History
Yes, got sick while sneaking slaves out. Slaves could not navigate and boat was taken and Walker arrested etc.
April 6, 2016

History
We can not tell. Gibberish. Reed is telling you you probably listed answers to another question. I told you south is wrong for sure. I am wondering if you are paying attention.
April 6, 2016

History
I do not know what Brace is being compared to but he shipped kids more from New York area West so not mostly southern.
April 6, 2016

College Algebra/pre-calculus
agree
April 6, 2016

physics
Be sure to check my arithmetic carefully !
April 6, 2016

physics
v = 6.58 so omega = 11 radians/second
April 6, 2016

physics
fell distance 4.05 so lost potential energy m g h = 3 * 9.81 * 4.05 That is kinetic energy of bucket plus spool v = omega R = .6 omega call omega = w Ke = (1/2) m v^2 + (1/2)I w^2 = (1/2)v^2 (m + I/.36) I = 5 * .5 * .36 = so I/.36 = 2.5 so 3 * 9.81 * 4.05 = .5 * v^2 *(5.5) ...
April 6, 2016

Physics miscounted
134.4
April 6, 2016

Physics
C = Q/v = 40*10^-6 Q = 40 * 10^-6 v i = dQ/dt = 40*10^-6 dv/dt let v = V sin wt dV/dt = V w cos wt so i = 40*10^-6 V w cos w t max i = 40*10^-6 V w w = 2 pi f = 2 pi(60) = 377 so max i = 40*10^-6 * 377 V so V = (2.26/(15080)) 10^6 =1344
April 6, 2016

Math help please
YOU MEAN sin^2 x=[ 1-cos(2x) ] /2 or 2 sin^2 x = 1 - cos(2x) cos 2 x = cos^2 x - sin^2 x so 2 sin^2 x = 1 - cos^2 x + sin^2 x sin^2 x = 1 - cos^2 x or sin^2 x + cos^2 x = 1 which is true
April 5, 2016

Physics
620 * .39 = x * 1.53 so (.39/1.53)620
April 4, 2016

Algebra
maybe you want: 3 7 2 3,7 3,2 7,2
April 4, 2016

English
Either but I would pick 2 because in the end the person, not the food, is supposed to be healthy.
April 4, 2016

Math
log3 (3m) log a + log b = log ab That is how a slide rule works. That is how old I am :)
April 4, 2016

PHYSICS!!!
ke at bottom = (1/2) m v^2 = (1/2) m (144) = 72 m Joules pe at top = m g h= m (9.81)(12.2 sin 18 = 37 m Joules so Lost 72-37 = 35 m Joules to friction Friction force = mu m g cos 18= 9.33 mu m work done by friction = 9.33 mu m * 12.2 = 114 mu m so 35 m = 114 mu m mu = 35/114...
April 4, 2016

PHYSICS!!!!
10 km/hr = 10/3.6 = 2.78 m/s 3 km/hr = 3/3.6 = .833 m/s 5 km at 10 km/hr --> 30 min which is 30 *60 = 1800 s energy = 700*1800 = 1.26*10^6 Joules 5 km at 3 km/hr --> 6,000 s 6,000 s * 300 w = 1.8*10^6 Joules ==============================
April 4, 2016

Physics
assuming that your potential energy is defined as zero at the bottom of the hill, all your energy is kinetic by the time you get there. 800 + 200 = 1000 Pert of this problem statement is missing though. In potentials, all you can define is differences. You have to define some ...
April 4, 2016

Math
2 pi r = 2 pi *7 = 14 pi inches
April 4, 2016

PHYSICS!!
change in potential energy = m g h = 2219*4*sin 30 = 4438 Joules = (1/2)mv^2 + (1/2)I w^2 but w = v/r = v/.4 = 2.5 v so 4438 = (1/2)(226)v^2 + (1/2)(22.6)(6.25 v^2) or 4438 = 184 v^2 so v = 24.2 m/s and w = 60.4 radians/s Torque * angle = change in Ke T * 2 pi = (1/2) I w^2
April 4, 2016

PHYSICS!!
first mass of rubber = 2000 * .3 * ∫ 2 pi r dr from r = .2 to r = .4 = 600 (2 pi) (1/2)(.16-.04) = 226 kg 226 * 9.81 = 2219 Newtons weight I = 2000*.3 *∫ 2 pi r^3 dr = 3770 (1/4)(.4^4-.2^4) = 22.6 ===================
April 4, 2016

PHYSICS!!
time = 100 * 3600 = 3.6 * 10^5 s so energy used= 120*3.6*10^5 = 432 * 10^5 Joules = m g h = 65 * 9.81 * h so h = .677 * 10^5 = 67,700 meters
April 4, 2016

Math
but 24 inches = 2 feet so r = 1 foot (4/3) pi (1)^3 = 4.19 ft^3 by the way 4/3 x 3.14/1 = 1.395 is wrong --- should be 4.19
April 4, 2016

Math
3/4 = .75 3/8 = .375 which is bigger?
April 4, 2016

Math
2(3.14 x 0.25) + 2(3.14)(.5)(4) answer in feet^2
April 4, 2016

no
You have to use all feet or all inches r = 0.5 feet NOT 6 inches
April 4, 2016

math
s + (s+30) = 36 2 s = 6 s = 3 f = 33
April 4, 2016

Math-soh cab toa
sin 30 = h/70 but we all know sin 30 = 1/2 so 35
April 4, 2016

Physics
final angular momentum about axis of rotation = initial angular momentum initial ang mom = 78*1.6 * 2 = 250 kg m^2/s final ang mom = 78 (2)^2 omega + 651 omega omega ( 963) = 250 omega = .26 radians/second
April 4, 2016

History
I would have chosen B A ---- interchangeable parts, came before assembly lines for example in weapons manufacture (Colt in Connecticut for example)
April 4, 2016

History
I suppose I have to agree, but we lost our forests here in Massachusetts to farming and wood stoves long before we had woolen mills and Springfield rifles. The really tall pines of course were marked with broad arrow symbols and reserved for the king's masts.
April 4, 2016

  1. Pages:
  2. <<Prev
  3. 4
  4. 5
  5. 6
  6. 7
  7. 8
  8. 9
  9. 10
  10. 11
  11. 12
  12. 13
  13. 14
  14. 15
  15. 16
  16. 17
  17. 18
  18. Next>>