Saturday
December 20, 2014

Posts by Damon


Total # Posts: 19,963

Calculus
Oh good grief, feet :( old text had initial speed 16 ft/s up ? I guess ? h = 32 + 16 t - 16 t^2 0 = 32 + 16 t - 16 t^2 solve quadratic t = [ -16 +/- sqrt ( 256+2048) ] /-32 t = 2 seconds v = dh/dt = 16 - 32 t = 16 - 64 = -48 ft/s
November 8, 2014

Algebra 2
4 x^2 + 2 x - 2 = 0 2 ( 2 x^2 + x - 1) = 0 (2x-1)(x+1) = 0 x = 1/2 or -1 5 x^2 + 34 x - 7 = 0 (5x-1)(x+7) = 0 etc
November 8, 2014

Algebra 2
http://www.gregthatcher.com/Mathematics/GaussJordan.aspx x= 1, y=2, z = 3
November 8, 2014

Calculus
x --> + oo of -x/e^x
November 8, 2014

Physics
sqrt (251^2 + 80^2)
November 7, 2014

Physics
How long to fall 10 meters? 10 = (1/2)(10) t^2 solve for t, time in air then 4 meters = u t solve foe u
November 7, 2014

Science Help!!!!
Yes, first it is burned in the engine to make CO2 The CO2 is used in photosynthesis to make wood and leaves and stuff, releasing the O2 for us to breathe.
November 7, 2014

physics
Problem entirely vertical assuming your straight line is horizontal Vi = 10 sin 46 v = Vi - g t delta h = Vi t - (1/2) g t^2
November 7, 2014

CAL
f'(x) or d f(x)/dx y' or dy/dx maybe?
November 6, 2014

Calculus
-4 cos^3 x^4 sin x^4 (4 x^3) = - 16 x^3 cos^3 x^4 sin x^4 how that is tan x2 whatever that is I can not imagine
November 6, 2014

Math
log 9 - log 300 2 log 4 + 4 log 3
November 6, 2014

Science
F2 + F1 = .450 (.750) F2 - F1 = .240 (.750) -------------------------- 2 F2 = .690(.750) etc
November 6, 2014

Physics
force down = 9.81*12 max friction force = 9.81 * 12 * mu forward force - friction force = m a 15 - 9.81*12 * mu = 12 (.2)
November 6, 2014

Math
I do not think so I think h = 300 - 16 t^2 she is accelerating DOWN 100 = 300 - 16 t^2 t^2 = 200/16 t = 10 sqrt 2 / 4 = 2.5 sqrt 2
November 6, 2014

Physics easier
http://outreach.phas.ubc.ca/phys420/p420_04/sean/
November 6, 2014

Hurricane Project for Physics Class
Physics (hard) http://www.psfc.mit.edu/library1/catalog/online_pubs/iap/iap2013/emanuel.pdf
November 6, 2014

Hurricane Project for Physics Class
Physics (hard) http://www.psfc.mit.edu/library1/catalog/online_pubs/iap/iap2013/emanuel.pdf
November 6, 2014

Hurricane Project for Physics Class
Click on hurricane in the upper right corner
November 6, 2014

Hurricane Project for Physics Class
http://coast.noaa.gov/hurricanes/#app=c64c&88cd-selectedIndex=1
November 6, 2014

Calculus
no v = w^2 h = (2300/3) h but h = (2300 -w^2)/4w
November 5, 2014

Calculus
v = w^2 h A = 2300 = w^2 + 4 w h 4 w h = 2300 - w^2 h = (2300 -w^2)/4w so v = w^2 [ (2300 -w^2)/4w ] v = 2300 w/4 - w^3/4 4 dv/dw = 2300 -3 w^2 = 0 for max w^2 = 2300/3 w = 27.7 cm etc
November 5, 2014

Math
2 w + 2 L = 18 so L = 9-w A = w L = 9 w - w^2 w^2 - 9 w = -A find vertex by completing the square for max A w^2 - 9 w + (9/2)^2 = - (A-81/4) (w -9/2)^2 = - (A-81/4) w = 9/2 for max area by the way that means 2 w = 9 and therefore 2 L = 9 so it is a square with sides = 9/2
November 5, 2014

Physics
No. To start it moving you must overcome the static friction. After that it gets easier. 648 * .86
November 5, 2014

algebra
sum of arithmetic series a1 = 1 d = 2 an = a1 + (n-1) d so a700 = a1 +(699)(2) sum = (a1 + a700)/n
November 5, 2014

calculus careful with parentheses
do you mean what you wrote 7 + 3 x^.5 or do you mean 3 [x+7]^.5 ??????????? anyway (x+1)(derivative of second) + (second) (1)
November 5, 2014

Calculus I
using T for theta dR/dT = (Vo^2 /9.81) cos2T (note max range when T = 45 degrees :) ) 100 dT/T = 2 dT = .02 T = .02 * pi/6 dR = (Vo^2 /9.81) cos2T dT 100 dR/R = cos 2T dT / sin 2T
November 5, 2014

physics
m g h = (1/2) m v^2 so h = (1/2) (v^2/g) mass has nothing to do with it
November 4, 2014

RIGHT TRIANGLE TRIG
You are welcome.
November 4, 2014

RIGHT TRIANGLE TRIG
sin 65 = h/150 assuming that the string hypotenuse is straight
November 4, 2014

Physics- linear acceleration
Find out how far the wagon went in 19 seconds d = (1/2) a t^2 = (1/2)(.3)(19)^2 each revolution or 2 pi radians the wheel rolls 2 pi r meters so divide d by (2*pi*.374) to find how many turns then multiply that by 2 pi to get radians (1/2)(.3)(19)^2 /.374
November 4, 2014

Math, Please Help! I don't understand!
I guess x is right and y is up final x = initial x + change in x final y = initial y + change in y beginning x = -2 moves one right -2 + 1 = -1 beginning y = -5 moves 3 up -5 + 3 = -2 b) (-1 , -2)
November 4, 2014

Algebra
f(f(x)] = p(px+q) + q f[f(f(x)) = p[p(px+q) + q] + q = p^2(px+q) + pq + q p^3 x + p^2 q + pq + q = 8 x + 21 = (p^3-8)x + p^2 q + pq + q = 21 this can not be a function of x or it would not be constant 21 so p^3-8 = 0 p = 2 4 q + 2q + q = 21 q = 3
November 4, 2014

Algebra
1. slope = 3 y = 3 x + b so to find b 2 = 0 + b b = 2 y = 3 x + 2 2. same way but slope = -1
November 4, 2014

Physics
find change in momentum .145(27+32) force = change in momentum/time = change in momentum /(1.5*10^-3 )
November 4, 2014

Physics
131 * 9.9 .00932 * 618
November 4, 2014

Calculus
x^2 - 6 = - y vertex on y axis, opens down (sheds water) so just do the right half half A = x y hA = -x (x^2-6) = -x^3 + 6 x dhA/dx = 0 at max = -3 x^2 + 6 x^2 = 2 x = sqrt 2 include left half length along x axis = 2 sqrt 2 if x = sqrt 2 y = 6 - x^2 = 6-2 = 4
November 4, 2014

Calculus
Oh, well I guess I found your point :) (15/26,5/13)
November 4, 2014

Calculus
rewrite as y = -(6/4)x + 1/4 line perpendicular has slope +4/6 = +2/3 y = (2/3) x + b we want it through 0, -1 -1 = (2/3) 0 + b b = -1 so y = (2/3) x - 1 where does that hit original line? (2/3) x - 1 = -(3/2) x + 1/4 4 x - 6 = -9 x + 3/2 13 x = 15/2 x = 15/26 then y = 5/13 ...
November 4, 2014

physics
change in momentum = .001 (300 - 700) time in block = .08/(average speed = .08 / [(700+300)/2] Force = change in momentum/time in block
November 4, 2014

Physics
F = m a solve for a then v = 0 + a t to get t: d = 3.3 = (1/2) a t^2
November 4, 2014

Physics
PLEASE CHECK FOR TYPOS slope of the air slope of air WHAT?
November 4, 2014

least to greatest fractions
6/9 is 2/3 if that is what you are asking. I have no idea what the second and third lines are about 4/40 is 1/10 2/5 is 4/10 maybe 7/10 is next ? 3/7 is 6/14 8/14 is 8/14 5/7 is 10/14 so next would be 12/14 = 6/7
November 3, 2014

math
y = 5 x + 100 your brother has the sign of the slope wrong
November 3, 2014

Algebra
q = [ (x+113)/2 ]^1/3 q = [ (137+113)/2 ]^1/3 q = 125^1/3 = 5
November 3, 2014

Math
-1.4 b = -28 b = 28/1.4 = 20
November 3, 2014

Algebra
y = x^5 - 1/3 inverse x = y^5 - 1/3 y^5 = x + 1/3 = -31/96 + 32/96 = 1/96 if y^5 = 1/96 then y =1/2.5 = .401
November 3, 2014

Calculus
cost of x tables = [160-.5(x-250)]x for x>/=250 c = 160 x + 125 x - .5 x^2 c = 285 x - .5 x^2 dc/dx = 285 - x max when x = 285 then c = .5*285^2 = 40,612.50 and c = 0 when x = 0 of course but also when x = 285*2 = 570
November 3, 2014

Algebra
f^-1(1) = 2 (when y = 1, x = 2) f^-1(2) = 5 f^-1(5) = 3
November 3, 2014

Physics
F = m a 12.1 = 5.9 a solve for a d = (1/2) a t^2 2.6 = (1/2) a t^2 we know a, solve for t v = a t
November 3, 2014

Algebra
x = 3 y^3 + 2 y^3 = (x-2)/3 so y = [ (x-2)/3 ]^(1/3) = f-1(x) so [ (x-2)/3 ]^(1/3) = 4 [ (x-2)/3 ] = 64 x - 2 = 192 x = 194
November 3, 2014

algebra
4 q = 5 * 18 2 q = 5 * 9 q = 45/2 = 22 1/2
November 3, 2014

Algebra
1,1 6,7 2,7 2,3 7,9 3,9 3,5 3,1 8,7 4,7 4,3 9,6 5,6 1,6 1,2 6,8 2,8 2,4 7,10 3,10 3,6 3,2 this thing is a pretty good vacuum cleaner, keep going until it repeats a point :)
November 3, 2014

Algebra
if y = x^2 - 2 x f(y) = (x^2-2x)^2 - 2(x^2-2x) = f(f(x)) so x^2-2x = (x^2-2x)^2 - 2(x^2-2x) of course x = zero will do :) let z = x^2 - 2x z = z^2 - 2 z z^2 - 3 z = 0 z (z-3) = 0 so another solution is x^2-2x = 0 = x (x-2 we already have x = 0 so now also have x = 2 and also ...
November 3, 2014

Algebra
I would have said something like that but have been having fun :) She has an imaginative teacher!
November 3, 2014

Algebra
y = (3x-7) / (x+1) inverse x = (3y-7) / (y+1) x y + x = 3 y - 7 3 y - x y = x + 7 y (3 - x) = (x+7) y = -(x+7)/(x-3) f^-1(x) = -(x+7)/(x-3)
November 3, 2014

physics
What you did makes sense to me. I guess we are assuming that the sphere has a very thin wall thickness to get the (2/3) m r^2
November 3, 2014

Math
(5/6 )24 = 20 pennies 20 / 50 = 2/5
November 3, 2014

Math
(2/5 )35 = 14 did not go in piggy bank (1/2) 14 = 7
November 3, 2014

trig actually, or maybe vector trig
4.19 cos 10.4
November 3, 2014

PHYSICS
lol - the other half of the problem 4.19 sin 10.4
November 3, 2014

Physics
emf = N d flux /dt emf = 660 B pi r^2 d/dt (sin 2 pi t/T) when t = .024, t/T = 1/8 T = .192 second so emf = -660 (pi r^2) (2 pi/T)B cos (2 pi t/T) now I do not know what "average means. Obviously the average of a cosine function is zero. You might guess they mean ...
November 3, 2014

Physics 11U
goes up from 2 to 8 or 6 meters do vertical problem v = Vi - g t 0 = Vi - 9.8 t at the top (8meters) so t at top = Vi/9.8 h = 2 + Vi t - 4.9 t^2 at top 8 = 2 + Vi t -(1/2)(9.8) t^2 6 = Vi t -(1/2)(9.8) t^2 6 = Vi^2/9.8 - (1/2) Vi^2/9.8 12 (9.8) = Vi^2 Vi = 10.84 m/s now do the...
November 3, 2014

Math Help!
well, 30 would be 900 and 28 would be 784 so do my proportion thing again 28 x 30 784 872 900 (872 -784)/ (x-28) = (900-784)/(30-28) x-28 = 2*88/116 x = 28 + about 1.5 or around 29.5 so 30 try calculator sqrt (872) = 29.529
November 3, 2014

math
speed = distance/time speed1 = 1020/3.30 speed2 = 1020/2.75 so speed2/speed1 = 1020/2.75 / 1020/3.30 = 3.30/2.75
November 3, 2014

Math Help!
go back and see how I did the earlier one with linear interpolation. It clearly works best when you pick perfect squares above and below the desired answer.
November 3, 2014

Physics
find induced EMF from 193 *area * dB/dt E = (193)pi (5.5*10^-2)^2 (.908) current = i = E/.241 now find B due to i B = mu N i/2 r = 4 pi*10^-7 (193)(i)/(2*5.5*10^-2)
November 3, 2014

Math Help!
15 --> 225 14 --> 196 13 --> 169 12 --> 144
November 3, 2014

Math Help!
x 3 z 4 y 9 14 16 linear interpolate (z - 3)/(14-9) = (4-3)/16-9) z - 3 = (5)(1)/7 z = 3 + 5/7 or a bit over 3.5 so pick 3.7 now use calculator 3.742 :)
November 3, 2014

Physics
(1/2) m v^2 = 182 m v = 27.6 so m = 27.6/v (1/2) (27.6/v) v^2 = 182 (1/2) (27.6) v = 182 etc
November 3, 2014

Help!-algebra
agree, c
November 3, 2014

Math Help!
In other words, Brady is right :)
November 3, 2014

Math Help!
0.8743 8743 8743 8743 * 10^-4 + 8743 * 10^-8 + 8743 * 10^-12 ...... repeating decimal, infinite geometric series a = 8743 r = 10^-4 sum = a/(1-r) = 8743 /(1 - .0001) =8743/.9999 = 87430000 / 9999 which is a rational number being the quotient of two integers/
November 3, 2014

Physics
initial mass = 73.5 + .21 initial momentum = (73.5 + .21)(2.97) final momentum is the same = .21 (29.3) + 73.5 v solve for v solve the second part the same way initial momentum = .21*29.3 = (.21+61.5)v
November 3, 2014

physics
calculate moment of inertia I alpha = change in angular rate/change in time = (34-0)/18 radians/second^2 Theta = (1/2) alpha t^2 Ke = (1/2) I w^2 tangent acceleration at rim = r * alpha radial acceleration = v^2/r = w^2 r where w = (1/2) 34 w (r/2) d = average speed * time but...
November 3, 2014

physics
actually Ke = (1/2) I w^2
November 3, 2014

Math
share as many sides as possible. Make it square :)
November 1, 2014

Physics
By the way, your formula is for the volume of a cylinder, not a sphere. Use (4/3)pi r^3
November 1, 2014

Physics
Volume of Glass = (4/3) pi (Ro^3 - Ri^3) mass of glass = rho V so 1.71 = 2660 (4/3) pi (Ro^3-Ri^3) so (Ro^3 - Ri^3) = 4.8214*10^-4 Now Archimedes assume rho water = 1000 1000 (4/3)pi Ro^3 = 1.71 solve for Ro^3 go back and get Ri^3 take cube roots :)
November 1, 2014

Statistics
and here is a calculator for it: http://www.neoprogrammics.com/linear_least_squares_regression/
November 1, 2014

Statistics
for example: http://mathworld.wolfram.com/LeastSquaresFitting.html
November 1, 2014

Statistics
I do not have your data. However if you have a bunch of points (x1,y1) , (x2, y2) .... (xn,yn) then you can fit a line of form y = m x + b that "best" fits those points, the criterion being that the sum of the squares of distances from the points to the line is ...
November 1, 2014

AP Calc. AB
y = 2 x + sin x if there were an inverse it would be x = 2 y + sin y 1 = 2 dy/dx - cos x dy/dx 1 = dy/dx (2-cos x) dy/dx = 1/(2-cos x) at x = 2 dy/dx = 1/(2-cos 2) = 1/(2 +.416) = .41
November 1, 2014

AP Calc. AB
because it does not pass the vertical line test. for every value of g there are multiple values of x because sin x is the same for many x values.
November 1, 2014

College Chemistry
370g/[(55.85 x 2) + (13 x 3)] = 2.32 mol Don't you mean 16 * 3 not 13 * 3 ?
November 1, 2014

calculus
Hey I did a couple. Now you do some.
October 31, 2014

calculus
at 1, y = 2 at 3, y = 0 dy/dx = -2x + 3 = 0 if x = 3/2 at x = 3/2, y = 2.25 so max at x = 3/2 and min at x = 3
October 31, 2014

calculus
df(x)/dx = 3 x^2 that is the slope at x = 3 slope = 3*9 = 27 so y = 27 x + b put in point at x = 3 to find b 27 =27 * 3 + b so -54 = b so y = 27 x - 54 at x = 2.7 y = 27 * 2.7 -54 = 18.9 the real answer would be y = 19.7
October 31, 2014

statistics
http://davidmlane.com/hyperstat/z_table.html
October 30, 2014

Geometry
yes correct m' = -1/m
October 30, 2014

Social Studies
Do you really think the former colonists would have won the war if they were a minority in the 13 colonies?
October 30, 2014

Social Studies
No, it is not a.
October 30, 2014

Social Studies
I thought I answered :) Looking at the link that Ms. Sue gave you, I think I answered correctly.
October 30, 2014

Social Studies
Oh, your answer to the Saratoga question is correct for sure.
October 30, 2014

Social Studies
I think c was true. I do not think more than half the colonists were Loyalists.
October 30, 2014

math
7 have black or brown total = 4+3+1+2 = 10 7/10 You can multiply top and bottom by 6 if you want, but no different :)
October 30, 2014

Calculus
3 * (x^10 - 1)^2 * 10 x^9 or 30 x^9 (x*10 - 1)^2
October 30, 2014

Algebra 2
20 x - 1 y = -200 25 x - 1 y = 0 D = -20 + 25 = 5 Dx = | -200 -1 | | +000 -1 | / 5 = 200/5 = 40 sign ? Dy = | 20 -200 | | 25 +000 | /5 = 5000/5 = 1000
October 29, 2014

Please help-algebra
yes
October 29, 2014

Please help-algebra
Jacqueline, please read the problem again.
October 29, 2014

Please help-algebra
no .15*number + 10 0.15 x + 10
October 29, 2014

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

Search
Members