Saturday
October 22, 2016

# Posts by Damon

Total # Posts: 27,510

math
.75 * 60 = .3 x x = .75 * 60 / .3 = 150
March 19, 2016

huh?
I do not understand your notation. What is po3-4 ????
March 19, 2016

Prob/Stats
p eat = .44 p not eat = .56 p that k say yes (binomial) P(17/k) = C(17,k) .44^k .56(17-k) where C(17,k) = 17!/[k!(17-k)!] do that for k = 8 through 17 and add OR approximate binomial expansion with normal distribution mean = n p = .44 * 17 = 7.48 sigma^2 = 17(.44)(.56) = 4.19...
March 19, 2016

math
.7 * 225 = 157.50 so no no 70% of original is 30% OFF original
March 19, 2016

mathematics
Huh Mauricio ????
March 19, 2016

mathematics
sketch it first length QR = 10 NOTE - perpendicular to x axis so altitude along x axis altitude from P to QR is along x axis and of length 9-3 = 6 so area = (1/2)(6)(10) = 30
March 19, 2016

binomial expansion help!!!
He said: Actually, just consider the definition of T. Take a peek here, and it should be clear, since the arc length is just ∫ ds = ∫ |dr/dt| dt 88888888888888888888888888 In other words the tangent is along the curve so if you integrate the tangent along the curve...
March 19, 2016

binomial expansion help!!!
You are welcome.
March 19, 2016

binomial expansion help!!!
(n+1)n(n-1)(n-2)/24 = 6 k is (n+1)n [(n-1)(n-2) ]= 72 * 2 k BUT [(n-1)(n-2)] = 2 k so (n+1) n = 72
March 19, 2016

binomial expansion help!!!
(1+x)^(n+1) = 1^(n+1) + (n+1)1^n x + (n-1)(n-2)/2 1^(n-1)x^2 + (n+1)n(n-1)/6 1^(n-2) x^3 +(n+1)n(n-1)(n-2)/24 1^(n-3)x^4 huum (n+1)n(n-1)(n-2)/24 = 6 k (1+x)^(n-1) = 1^(n-1) + (n-1)1^(n-2) x + (n-1)(n-2)1^(n-3)/2 * x^2 so (n-1)(n-2)/2 = k (n-1)(n-2) = 2 k so (n+1)n (2k)/24 = 6...
March 19, 2016

Math
they have 4/5 2/5 and 2/5 3/5 and 1/5 1/5 and 3/5 or many others like if we say 4/5 = 8/10 or even 16/20 1/10 and 7/10 etc :)
March 19, 2016

math
3/4 cup / 1/4 tbsp = 3 cups / 1 tbsp
March 19, 2016

Phys 2425
between wires field is down from one of them and up from the other The B from a wire times 2 pi * distance from the wire is proportional to the current through so 1/2pir = 2/ 2pi(2 -r) 2 r = 2 - r 3 r = 2 r = .66666666667 cm :)
March 18, 2016

Pre algebra
2 w = L/2 or L = 4 w perimeter = 2(L+w) = 2( 5 w) = 10 w = 10 so w = 1 L = 4
March 18, 2016

Physics
momentum = m v = .025 * 300 stops in .03 meters average speed during stop = 150 m/s time to stop = .03 meters/150 m/s force = change in momentum/time = .025 * 300 / (.03/150) = 37,500 N do B the same way
March 18, 2016

math
a + b + c = 408 b = c + 7 so c = b-7 b = a + 5 a + (a+5) + (a+5-7) = 408 3 a + 3 = 408 a + 1 = 136 a = 135
March 17, 2016

mAth
You are welcome.
March 17, 2016

mAth
[ (x-2.6)/0.3 ] 3 = -48 (x-2.6)/0.3 = -16 x - 2.6 = -4.8 x = -2.2
March 17, 2016

math
4/5 * 3/4 * 2/3 = what was left in the end = .4 of original is left at the end call original amount 1 then youngest gets .2 that leaves .8 then middle gets .8/4 = .2 as well that leaves .6 oldest gets .6/3 = .2 ROTFL !!!
March 16, 2016

algebra
short leg = x long leg = x+8 hypotenuse = 2x-8 so { 2(x-4) }^2 = x^2 + (x+8)^2 4 (x^2 - 8 x + 16)= x^2+x^2+16x+64 4x^2 -32 x + 64 = 2 x^2 +16 x + 64 2 x^2 -48 x = 0 x = 0 works but x = 24 ******************* check 24 , 32 , 40 or /8 3 , 4, 5 LOL yes, right triangle
March 16, 2016

Geometry
As the problem is stated, of course they will because as it rises the horizontal distance from the pivot point at the ground decreases. If the wires are exactly above the tip of the bean at 60 deg, then they will be closer to the pivot point at more than 60deg Therefore I ...
March 16, 2016

Math
12 * 20 * 7 * 8
March 14, 2016

physics 11th class
m g h / t
March 14, 2016

ratios/algebra
8/5 = 64/x 40
March 14, 2016

Physics
heat to melt + heat to raise 10 deg = m * heat of fusion + m *specific heat * (10-0)
March 14, 2016

Math
t = k L/n 6 = k 4/100 so k = 150 t = 150 (16/160) = 15 weeks
March 11, 2016

Chemistry
only if you know the molar mass of each and the balanced equation so you can see how many moles and therefore grams of A are needed to react with B. So in general, No
March 11, 2016

Math
it was evidently launched straight up in which case: h(t) = 73.5 + 9.8 t - (1/2)g t^2 g is about 9.81 m/s^2 so h(t) = 73.5 + 9.8 t - 4.9 t^2 at ground, h(t) = 0 so 0 = 4.9 t^2 - 9.8 t - 73.5 and yes you can take 4.9 out approximately 0 = t^2 - 2 t -15 (t-5)(t+3) = 0 t = 5 seconds
March 11, 2016

Algebra
F = k m g v^2/R (actually k g = 1 because v^2/R is centripetal acceleration) anyway 400 = k (1600) 50^2/800 so k(1600) = 800 * 400 /2500 F = k (1600) 60^2 /600 F = 800*400 *3600 /{2500*600) = (8/6)(36/25)*400 = (4/3)(36)(16) = 768 pounds
March 11, 2016

huh?
pi r^2 = 3.14 * 64 ft^2
March 11, 2016

Science
14 agree 15 I suppose but just the word "vital" would do. Depends on what your text says. These questions stink. 16 yes (and that gives away the earlier question :) 17 Heat? Depends on what your particular text says again. 18 yes, evaporates 19 consumer ? 20 yes, ...
March 11, 2016

Science
8 no idea, check your text for screwy comparison 9 yes d eats plants and fish 10 c yes I suspect 11 I bet on a 12 b I think but minor effect 13 a yes
March 11, 2016

Science
7 d I think, no light
March 11, 2016

Science
1 yes 2 no idea what they are getting at. Merry go round correct for physics, not biology 3 c yes 4 yes, came on Mayflower :) 5 c yes 6 c yes
March 11, 2016

maths
r = 44/2pi = 7 cm area = pi (49) = 154 cm^2 square side = 11 area = 121 cm^2
March 11, 2016

math and science
v = Vi + a t 0 = 36 + a t t = -36/a d = Vi t + .5 a t^2 40 = 36 (-36/a) + .5 (a)(36^2/a^2) 40 = - 36^2/a + .5 *36^2/a 80 a = -36^2 a = -16.2 m/s^2 then F = m a = -1500(16.2) Newtons
March 11, 2016

Math
2 x + y = 320 x y = 12,600 so y = 12,600/x 2 x + 12,600/x = 320 x^2 + 6,300 = 160 x x^2 - 160 x + 6,300 = 0 x = [160+/-sqrt(25600-25200)]/2 x = [ 160 +/- 20] /2 x = 90 or 70 try 90 then y = 140 2x + y = 320 Yes, that works try 70 y = 180 2x+ y = 140 + 180 = 320, Yes that works
March 11, 2016

math
multiply both sides by -1 (-1)(-y) = + y (-1)(3) = -3 so y = -3
March 11, 2016

math
2 ends are 16*14 2 sides are 4.8*14 top and bottom are 4.8 * 16 so 2(16*14 + 4.8*14 + 4.8*16)
March 11, 2016

math
13 + 13 = 26 13 hearts and 13 clubs
March 9, 2016

Math
y = 10 x + 4 (-2, -16) (-1 , -6) (0 , +4} (1 , 14) (2 , 24)
March 9, 2016

Math
slope = (-6+1)/(1-0) = -5 so y = -5 x + b 9 = 10 + b b = -1 so y = -5 x -1 or 5 x + y = -1
March 9, 2016

PHYSICS ( PERIODIC MOTION)
if damping proportional to v F = -kx -bv then x = A e^-(bt/2m) sin w' t five cycles is about 3.67 seconds so 1/2 = e^-(3.67 b /.226) take ln both sides -.693 = - -16.2 b so b = .0427 then w' = sqrt (k/m -b^2/4m^2) = sqrt (73. - .035) =8.542 = 2 pi/T T = .7355 s change ...
March 9, 2016

PHYSICS ( PERIODIC MOTION)
mass = .1136 kg g = 9.81 m/s^2 so weight = .1136*9.81 = 1.114 Newtons spring constant k = 1.114 N/ .134 meters = 8.32 N/m T = 2 pi sqrt(m/k) = 2 pi sqrt (.1136/8.32) = 0.734 s = 7.34 * 10^-1 s
March 9, 2016

Maths
(1/2)M + (1/3)M + 40 = M multiply by 6 3 M + 2 M + 240 = 6 M 240 = M spent M-40 = 200
March 9, 2016

Science
In English units, the acceleration of gravity near the surface of earth is about 32 feet/second^2 = g When we used those units, we defined mass in slugs. mass in slugs m = weight in pounds/g = weight in pounds/32 Then we could use Newton's second law F = m a where force is...
March 9, 2016

Math
one is 16 * 5 the other is (40 - 5) = 35 *5 so 80 *5 [ 16+35 ] = 80*5*51-
March 9, 2016

Physics
In English units, the acceleration of gravity near the surface of earth is about 32 feet/second^2 = g When we used those units, we defined mass in slugs. mass in slugs m = weight in pounds/g = weight in pounds/32 Then we could use Newton's second law F = m a where force is...
March 9, 2016

english
verbs like worked SLOWLY or ate quickly An ly at the end is a dead giveaway but is not always the case.
March 9, 2016

Lets complete the square to look at the parabola y = -2x^2+16x+40 x^2 - 8 x -20 = -y/2 x^2 - 8 x = -y/2 + 20 x^2 - 8 x + 16 = -y/2 +36 (x-4)^2 = -(1/2)(y-72) so max area occurs when x = 4 and area = 72 zeros are when x^2-8x-20 = 0 (x-10)(x+2) = 0 or when x = 10 and when x = -2...
March 9, 2016

Math
25 x >/= 5000 x >/= 200
March 8, 2016

Physics HW Plz help
the fundamental frequency is called the first harmonic Higher harmonics are integer multiples of the fundamental we know 24/3 = 8 1 f = 8 2 f = 16 3 f = 24 4 f = 32 5 f = 40 6 f = 48
March 8, 2016

Algebra
LOL, yes, just use a square
March 8, 2016

2/x^2 = 8/(12-x)^2 1/x^2 = 4 /(12-x)^2 4 x^2 = 144 - 24 x + x^2 3 x^2 + 24 x - 144 = 0 x^2 + 8 x - 48 = 0 (x+12)(x-4) = 0 x = 4 cm then 12 - x = 8 cm check 2/16 = 8/64 ??? yes right
March 8, 2016

math
.06 * 300 = 18 empty (answer) .06 * 310 = 18.6 do not show of the 310 310 - 18.6 = 291.4 show up (answer) additionally 300 seats - 291.4 passengers = 8.6 empty seats which is really 18 empty because 40% of a passenger takes a whole seat
March 8, 2016

math
.98 * 15,000 = 14,700 Only 2 percent will arrive late so your flight will probably be on time. Of course the key word is "probably" and there is no way you can tell if yours is one of the two out of one hundred that are late.
March 8, 2016

No diagram
If you tried to copy and paste a picture, that does not work.
March 8, 2016

math
0.06 * 500 = 36
March 8, 2016

history
http://en.wikipedia.org/wiki/Afro-Asian
March 8, 2016

math
20 * 8 = 160 player days 0.80 * 160 = 128 player days or an average of 16 players/day
March 8, 2016

phy 231
x = 1.5 sin (2 pi * .181 t) = 1.5 sin (1.137 t) v = dx/dt = 1.5* 1.137 cos (1.137 t) v max = 1.5 * 1.137 a = d^2x/dt^2 = -1.5*1.137^2 sin (1.137 t) a max = 1.5 * 1.137^2
March 8, 2016

physics
surface tension is force/length I am going to call density rho, not P. P is confusing because usually pressure. F = m a = rho L^3 * L/s^2 = rho L^4/s^2 so F/L = rho L^3/s^2 but g is L/s^2 so F/L = rho L^2 g if our length scale is h then Y = F/L = constant * rho h^2 g By the ...
March 7, 2016

math help fast
http://www.mathsisfun.com/algebra/sequences-sums-arithmetic.html
March 7, 2016

math help fast
http://www.mathsisfun.com/algebra/sequences-sums-geometric.html
March 7, 2016

math help fast
2. -4,8,-16,32,... -4 to + 8 is +12 then it goes DOWN 12 so not arithmetic, different d now is it geometric? 8/-4 = -2 -16/8 = -2 32/-16 = -2 = r SO GEOMETRIC next term is 32 * -2 = -64 so the middle one. I do not understand why you are having trouble with these.
March 7, 2016

math help fast
#1 is Arithmetic with d = 5 It is NOT geometric r = 29/24 = 1.208 r = 19/14 = 1.357 1.208 is NOT 1.357
March 7, 2016

matg
if in degrees sum of angles in triangle = 180 x - 7 + x + 3 x + 2 = 180 5 x - 5 = 180 5 x = 185 x = 37 x-7 = 30 3x+2 = 113
March 6, 2016

Physics 12
length on table = x length over side = 2-x mass/meter length = m mass on table = m x max friction force =.5 m g x mass over the side = m(2-x) weight over the side = m g(2-x) if slips when .5 m g x = m g (2-x) x = 2 (2-x) 3 x = 4 x = 4/3 = 1.33 meter = 133 cm
March 6, 2016

physics
Vi = 36 u = 64 tan A = 36/64 |v| = sqrt (36^2 + 64^2) = 4 sqrt(337)
March 6, 2016

regroup to +700 +120 + 3 -200 - 70 - 3 ------------------ +500 + 50 + 0 or 550
March 6, 2016

Networks, Matrices, Linear equations.
I think the total to X is .2*3000 + .5*2000 + .7*5000 X = |.2 .5 .7 | times the column 3000 2000 5000 so I would write { X Y } column= |.2 .5 .7| |.8 .5 .3| times the column 3000 2000 5000
March 6, 2016

maths
well their difference is one :) 4 + 5 = 9
March 6, 2016

Physics
Momentum is conserved period. total kinetic energy conserved? No, where did you get that idea? Think about a bullet hitting a block and getting embedded. I am sure you have done that for homework. You solve it using conservation of momentum. However (1/2)m V^2 of bullet is not...
March 5, 2016

science
with a simple pendulum period of pendulum = 2 pi sqrt (L/g) ------------------------ with a scale Using a 1 kg weight force down on scale = m g in Newtons, weight = mass in kg * g so g in m/s^2 = weight in newtons / mass in kg Of course your scale is likely to show kilograms ...
March 5, 2016

physics
If those are at consecutive corners, they cancel each other.
March 5, 2016

Physics
net force up = 800- m g
March 5, 2016

Algebra
halfway between 1/2 and 1/10 is (.5 + .1)/2 = .3 = 3/10 not 1/6
March 5, 2016

Algebra
1/10 = 3/30 1/6 = 5/30 ---------- subtract d = -2/30 = -1/15 check it first two points d = 5/30 - 15/30 = -10/30 = -1/3 This is not an arithmetic progression, typo.
March 5, 2016

trigonometry
You fly on a "heading" not a "bearing". You take a "bearing", the direction of something, like a lighthouse, from you. Mathematicians are terrible navigators. That said: 60 deg 20' = 60.33 degrees clockwise from North which is 29.67 above +X ...
March 5, 2016

math
x (x-3) is supposed to be negative if x >3 it is positive if x <0 it is positive it is only positive * negative = negative between 0 and 3
March 4, 2016

math
Do I get extra credit for finding a harder way ?
March 4, 2016

math
cos x/sin x + sin x/(1+cos x) = 0 ?? nah, maybe you mean (1+cos x)/sin x + sin x/(1+cos x)=1 (1+cos)(1-cos)/(sin(1-cos)) +sin (1-cos)/[(1+cos)(1-cos)] = 1 (1-cos^2)/(sin-sin cos) + (sin-sin cos)/(1-cos^2) = 1 sin/(1-cos) + (1-cos)/sin = 1 sin^2 + (1-cos)^2 = sin(1-cos) (1-cos^...
March 4, 2016

physics
It has to get 40 m high when it gets 40 m high, it must have a centripetal acceleration of 1 g or it no longer touches its track. so Ac = v^2/r = 9.81 m/s^2 v^2 = 20*9.81 v = 14 m/s now it has to drop a distance m g h = (1/2) m v^2 to the TOP of the wheel h - 40 = .5 v^2/g but...
March 4, 2016

Physics
normal force = m g cos 26.8 so friction force = .26 m g cos 26.8 force down slope = m g sin 26.8 so m g sin 26.8 - .26 m g cos 26.8 = m a a = g [ sin 26.8 - .26 cos 26.8]
March 4, 2016

Math
the area of a cube divided by the volume? 6/s did you use a + where it should have been = ? area of sphere divide by volume ? 3/r area of right circular cylinder divided by volume ? 2/h + 2/r = 2 (r+h)/rh
March 4, 2016

Sorry, all I have time for
That is all I can try tonight.
March 3, 2016

calculus
b) Let z = x + iy. Obtain the real and imaginary parts of the function f(z) = 1/(1+z) I assume f(z) = 1/[(1+x) +iy ] = [(1+x)-iy] / {[(1+x) +iy ][[(1+x)-iy] } = [(1+x)-iy] /{(1+x)^2 +y^2} = (1+x)/{(1+x)^2 +y^2} - i y /{(1+x)^2 +y^2}]
March 3, 2016

calculus
T is theta z = r e^iT = r (cos T + i sin T) z^3 = r^3 e^3iT = -1 if r = 1 e^3 i T = -1 = cos 3T + i sin 3T 3T can be pi or 3 pi or 5 pi so T = pi/3 or pi or 5 pi/3 so z = e^i(pi/3) or e^i(pi) or e^i(5 pi/3) for pi/3 z = cos pi/3 + i sin pi/3 = .5 + .866 i for pi z = -1 (well ...
March 3, 2016

Physics
angular momentum before =I w=.19 * .0684 + .486(.418)^2*0 = .013 new I w = (.19 +.085)w so .013 = .275 w w = .047 rad/s
March 3, 2016

Weight Is Force! Science
where it has a mass of 390000 N that is a typo should be where it has a WEIGHT of 390000 N m g = w 9000 g = 390,000 g = 390/9 = 43.3 m/s^2
March 3, 2016

physics
Ac = v^2/r v increases but there is no radial force so v^2/r has to be the same so r has to increase.
March 3, 2016

No
I choose 2 2+4 is LESS than 7
March 3, 2016

Math
y = 3 x y = x^2 y = sin x then relations that are not functions y^2 = x or y = x^(1/2) two values of y for every x y = sin^-1 (x) for every x there is an infinite number of y values like if x = 1/2 y = 30 deg, y = 150 degrees etc x y 1 -1 0 0 1 1
March 3, 2016

Math
well, 2 a b = 0 so either a = 0 or b = 0 or both :) b ) let me see 5 - 5 = 0 I think true c) I suppose so d) sure n/1
March 3, 2016

Math
(52 g/85 cm) 10 cm = 6.12 g
March 3, 2016

Math
find probability that all are green first one 4/9 second one 3/8 third one 2/7 all green = (4/9)(3/8)(2/7) answer = 1 - that result ============================= find probability that 9 of 9 are red find probability that 8 of 9 are red that sum is the probability that zero or ...
March 3, 2016

Physics
weight = 7 * 9.81 Newtons force down slope = weight * sin 30 = (1/2)weight force up slope = 381 N net force up slope = 381 -(1/2) weight = 347 N a = F/m = 347/7 = 49.5 m/s^2 v = 5 + a t v = 5 + 49.5 t distance = average speed * t 9 = (1/2)(v+5) t 18 = (10+49t) t 49 t^2 + 10 t...
March 3, 2016

physics
power = work/time since the time is the same, the power ratio is the work ratio work in = kinetic energy out kinetic energy proportional to v^2 [ like (1/2)m v^2 ] v'^2/v^2 = 16
March 3, 2016

math
1/3 of a pint = 1/3 of 1/2 qt = 1/6 qt or 1/3 of 2 cups = 2/3 cup 1/3 pint * (1 gal/8 pints)(1 barrel/55 gallons = 1/(3*8*55) = 1/1320 barrels :) or whatever
March 3, 2016

PHYSICS HELP
(a) m g = 9.81 * 4.5 = 44.15 N (b) 44.15 cos 12 (c) 44.15 cos 25 (d) what else is new?
March 3, 2016