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March 23, 2017

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Posts by Damon

Total # Posts: 29,612

calculus
dh/dt = -9.8 t + 10 when t = 1 dh/dt = 10-9.8 = 0.2
October 15, 2016

math
x y change in y/change in x which is slope -2 9 ****** -5 -1 4 ****** -5 0 -1 ****** -5 1 -6 ****** -5 2 -11 hmmm, constant slope = -5 y = -5 x + b 9 = -5 (-2) + b 9 = 10 + b b = -1 so y = -5 x -1 answer check at last point -11 = -5(2) -1 -11 = -10 - 1 yes, good
October 15, 2016

Cousino
speed upstream = 8 - u speed downstream = 8 + u time upstream = 5/(8-u) time downstream =5/(8+u) so 5(8-u) + 5/(8+u) = (4/3) hr 5(8+u) + 5(8-u) = (4/3)(64-u^2) 15(8+u) + 15(8-u) = 256(64-u^2) etc, solve quadratic
October 15, 2016

be careful with parentherses
do you mean 1/(2a) or (1/2)a 1) f(-2) = 4 a^2 +2a + 3b = 4 a^2-b+8 f(-3) = 9 a^2 +3a + 3b = 7a^2-b+14 so 2 a + 3 b = - b + 8 2 a + 4 b = 8 a + 2 b = 4 or a = 4 - 2 b and then 2 a^2 + 3 a + 4 b = 14 2(16 - 16 b +4b^2) + 3(4-2b) +4b=14 32 -32b +8b^2+12 -6b +4b = 14 30 + 8b^2 -...
October 15, 2016

physics
v = velocity up = 30 sin 30 - 9.81 t u = velocity horizontal = 30 cos t if t = 1 v = 15 - 9.81 u = 30(.866) speed = sqrt (u^2+v^2) tan angle up = v/u
October 15, 2016

math
as y--->0 cos y = 1 - y^2/2 + ........ numerator: 2 - 1 +(1/2)(9)x^2 -1 +(1/2)(16)x^2 0 + (25/2)x^2 oh my now divide by x 25 x/2 goes to 0 as x goes to 0
October 15, 2016

math
by the way tangent of small angle approaches sine of that small angle :) theta + theta^2/2 .......
October 15, 2016

math
Hey, I did the other one, try series approach on this one too.
October 15, 2016

math
m = math only s = science only b = both = 10 31 = m + b = m + 10 so m = 21 s+b = 36 - m s + 10 = 36 - 21 s + 10 = 15 so = Answer all science students s = 5 only science ======================== check 21 + 10 = 31, yes all math students 5 + 10 = 15 , yes all science students 21...
October 15, 2016

Pre-calculus
This is what it is about: http://www.youtube.com/watch?v=zw0waJCEc-w sin 45 = (1/2)sqrt 2
October 15, 2016

Pre-calculus
well, 7 = 6 + 1 so it is really sin (6 pi/12 + pi/12) sin(a+b) = sin a cos b + cos a sin b (just like your other problem) sin 6 pi/12 = sin 90 = 1 cos pi/12 = cos 15 deg cos 90 = 0 so cos 15 degrees
October 15, 2016

Math
y = k/x^3 new y = k/(x/2)^3 = 8 k/x^3 8 times as big
October 15, 2016

english
I have made 100 ship models in my life. I had made 100 ship models when they told me to stop and start doing physics problems.
October 13, 2016

Maths
9 km/(3/2)hr = 18/3 = 6 km/hr
October 13, 2016

Math- Please check my answer!
6/8 = 60/80 8/10 = 64/80
October 13, 2016

Math
2 driveways/day * 5 d/w = 10 driveways/week 10 driveways/week * 50 work weeks/yr = 500 driveways/year Now as Myah said, what is the question?
October 13, 2016

physics
heat of fusion * 150 g + 150 * heat capacity* (T-0) = 300 * heat capacity*(50-T)
October 13, 2016

Physics
normal forces 5 kg block: 5(9.81) 10 kg block 5*9.81 and 15*9.81 forces 5 kg block .2 * 5 * 9.81 right T left no acceleration so T = .2 * 5 * 9.81 = 9.81 N (answer to part C by the way) 10 kg block T left .1 * 15 * 9.81 left 45 N right so 45 - 9.81 - .1*15*9.81 = 10 a the end
October 13, 2016

physics
h = 1 = (1/2)(9.81)t^2 (a)solve that for t, the fall time u t = 1.5 (b)so u = 1.5/t v = g t = 9.81 t speed = sqrt (u^2+v^2) tan angle below hor = |v|/u
October 13, 2016

8th Grade Math
y = k x -12.5 = 50 k -25 = 100 k k = -1/4 y = -x/4 y = - (47/4) / 4 = - 47/16
October 12, 2016

math
(5)(3/13) - 2(10/13) = -5/13 You better stay away from this game. There are 13 cards in each suit of which 3, the jack, queen and king are winners. The other 10, ace through 10, are losers
October 12, 2016

Physics
If it is moving to the left, the frictional force is pushing right. 0.6 * 90 * 9.81 yes, looks about right but stick to 3 significant figures.
October 12, 2016

algebra
(0,13) (13,0) and (0,0) completes triangle that is half a 13 by 13 square area = 169/2
October 12, 2016

environmental science
Ah, almost but your understanding of feedback is backwards. Negative feedback means the output is fed back and inhibits further growth in the output, stable Positive feedback means the output is fed back and INCREASES growth in the output, UNSTABLE. This is what they are ...
October 12, 2016

environmental science
well, I guess natural gas is higher quality than most of what you find in a landfill :) It all depends on their definition of "near" the surface though.
October 12, 2016

History
LOL - yes, stamps and tea are different from each other.
October 12, 2016

Physics
total energy at top = (1/2)(1530)(36) + 1530(9.81)(115) total energy at bottom = (1/2)(1530)(27)^2 work done = energy at top - energy at bottom average velocity = (27+6)/2 time = 4400/average velocity power = work done/time
October 12, 2016

Statistics
binomial distribution p(n,k) = C(n,k)p^k (1-p)^(n-k) p(3,1) = C(3,3) .38^3 * .62^0 = 1 * .38^3 * 1 do c next because b is 1 - c p(3,0) = 1 * 1 * .68^3 now b = 1 - c = 1 - .68^3
October 12, 2016

Science
The word "compound" is a dead giveaway.
October 12, 2016

Physics
ice is about 2.03 Joules/ gram deg c so 2030 J/kg deg c 1.2 kg *2030 J /kg degC (-15-T) = 20,000 J
October 12, 2016

Physics
v cos 30 = 110
October 12, 2016

Chemistry
.37* 500 = .96 x where x is the amount of strong stuff you put in 500 - x is the amount of water
October 12, 2016

Science
which answer uses the word "compound"?
October 12, 2016

Math. please help
-1/2 = -3/6 +1/3 = 2/6 does that help ?
October 12, 2016

Differential Calculus
find radius of surface as a function of height h r/h = 5/10 = .5 then surface area = pi r^2 = pi (.25 h^2) change in volume dv = surface area * dh dv = pi (.25 h^2) dh and dv/dt = .25 pi h^2 dh/dt 4 = .25 pi (9) dh/dt solve for dh/dt
October 11, 2016

algebra 1
50 mi/h * 5280 ft/mi *1 h /3600 s mi cancels h cancels we are left with 50 * 5280/3600 ft/s = 73 ft/s
October 10, 2016

error !
french alone = f history alone = h both = 8 f+8 - 10 = h+8 or f-h = 10 and f+h + 8 = 40 or f+h = 32 so 2f =42 f = 21 h = 11 so f+8 = 29 study french or both h+8 = 19 study history or both
October 10, 2016

Venn Diagram
french alone = f history alone = h both = 8 f+8 - 10 = h+8 or f-h = 8 and f+h + 8 = 40 or f+h = 32 so 2f =40 f = 20 h = 12 so f+8 = 28 study french or both h+8 = 20 study history or both
October 10, 2016

American Governement
I would be inclined to favor A, balance of power.
October 10, 2016

American Governement
Yes, right, A
October 10, 2016

Chemistry
.12 * 207 grams
October 10, 2016

value
(1/2)(100)(64) Joules
October 10, 2016

Chemistry
LOL, not observable I am sure h/(mv) = 6*10^-34 / (.05*40)
October 10, 2016

Math
Two problems: 1. x-8 -15 = -6 2. -x+8 -15 = -6
October 10, 2016

algebra
3000 = 1000 e^10 k 3 = e^10k ln 3 = 10 k solve for k n = 1000 e^5k with same k do e^5k on your calculator
October 10, 2016

social studies
They are in it !!!
October 10, 2016

Math/ Algebra
I did not miss a sign. 1/3x is not x/3
October 10, 2016

Math/ Algebra
well, if it is actually 14 = (1/3) x + 5 or 14 = (x/3)+ 5 then that is 14 = (1/3)27 + 5 14 = 9 + 5 yes however 14 is not 1/ (3*27) + 5
October 10, 2016

Math
m marbles in bag 2m/5 are red so 3 m/5 = b+y m = r + b + y b/y = 5/7 or y = 7b/5 3 m/5 = b + 7b/5 3 m/5 = 12 b/5 4 b = m b = (1/4) m
October 10, 2016

physics
I gave you the frequency and the rotational speed because I do not know what "rotational frequency" means.
October 10, 2016

physics
v^2/r = 6 m/s^2 so v^2 = 86.5 *6 v = sqrt (86.5*6) T = pi d /v = pi(173)/sqrt(86.5*6) f = frequency = 1/T omega = 2 pi f = 2 pi/T = 2 sqrt(86.5*6) / 173
October 10, 2016

Science
no F = m a big F is big m times big a
October 10, 2016

TECH ED HELP
I agree with kara.
October 10, 2016

Math
agreed on the first 2, there is no answer for number 2 but the third 2y = 2x-6 y = x-3 slope = 1 your -3 is b in y = m x + b, the y axis intercept
October 10, 2016

Calc I (@Reiny)
Reiny already did this for you. Yes, right.
October 10, 2016

physics
vertical force = m g - F sin 38 horizontal force =.42*vertical force - F cos 38 when the horizontal force is zero, it is about to accelerate so when F cos 38 = .42 (85*9.81-F sin 38) solve for F
October 10, 2016

math
3/24 = 1/8 = .125
October 10, 2016

Statistics
http://davidmlane.com/hyperstat/z_table.html
October 9, 2016

ashworth
Google subjunctive of was: http://www.google.com/search?q=subjunctive+of+was&ie=utf-8&oe=utf-8 he approves not we approve
October 9, 2016

computer
LOL, this depends on the level of detail. I am not going to do an entire flow chart for Turbotax deluxe :)
October 9, 2016

chemistry
to raise the temperature of 1 kg of Aluminum one degree centigrade you must put in 900 Joules of heat energy.
October 9, 2016

math(Quantitative) ...Pls help me
(b) maybe time of year, exchange rate for currency
October 9, 2016

math(Quantitative) ...Pls help me
well, your guess is as good as mine but (a) number of football games, depth of snow (b) Legon Ghana? (c) number of hurricanes in past 12 months, number of arrests of bank officers (d) month of the year, number of weddings scheduled for week
October 9, 2016

Maths
(1/2) g/cm^3 or 500 kg/m^3
October 9, 2016

chemistry
http://www.google.com/search?q=ch3oh+lewis+structure&ie=utf-8&oe=utf-8
October 9, 2016

math
pi/2 3 pi/2 and I suppose -pi/2 -3 pi/2
October 9, 2016

math
so she buys all red ribbon ! 20/1.59
October 9, 2016

Physics
zero, it came back
October 9, 2016

physic
.5 (840)(T-16) = 2(4200)(25-T)
October 9, 2016

Physics
zero Displacement is a VECTOR this ball moved up, then down. It therefore moved zero meters in no direction. They did NOT ask for DISTANCE
October 9, 2016

Math
C(16,4) = 16! / [ (16-4)!(4!) ] =16*15*14*13/(4*3*2) = 4 * 5 * 7 * 13 = 1280 Oh well
October 9, 2016

math
21/2 = 10.5 so try 10 + 11
October 9, 2016

physics
143 = m g + m a = m (9.81+0.762) m = 143/(9.81+.762) weight = m g
October 8, 2016

physics
g(Re/r)^2 = (1/4)(9.81)
October 8, 2016

physics
6.5 * 10^5 I expect you mean and 1.8*10^7 F = m a 6.5 * 10^5 = 1.8*10^7 a a = 3.61*10^-2 m/s^2 90 km/h (1 h/3600s)(1000 m/km) = 25 m/s v = a t 25 = 3.61*10^-2 t t = 6.93 *10^2 s = 693 s = 11.5 min
October 8, 2016

Interferometry carried to an unimaginable (for me) extreme
You better Google LIGO, but that is the whole thing. There is no simple reply really.
October 8, 2016

physics
6 g - T = 17 a T - mu(11 g) = 11 a what is a? d = (1/2) a t^2 1 = (1/2)a(1.48)^2 a = .913 m/s^2 6 g - T = 15.5 so T = 6 g - 15.5 so 6 g - 15.5 - 11 g mu = 10.0 let g = 9.8 and solve for mu
October 8, 2016

Math
LOL, cost / number of sprays
October 8, 2016

physics
vertical: Ftop = mg + Tt = m v^2/R Fbot = Tb-mg = m v^2/R so max is Tb = m g + mv^2/R so mg +Tt = Tb-mg 2 mg = Tb-Tt LOL, could have guessed Horizontal T = m v^2/R given Tb = 1.066 T mg + mv^2/R = 1.066 mv^2/R g = .066 v^2/R so v^2 = g R /.066
October 8, 2016

Maths
one at x = 0 then 10 more at 5, 10, 15, 20, 25 , 30, 35, 40, 45, 50 You always have one more fence post than panels of fencing
October 8, 2016

Maths
50/5 + 1 = 11 (one is at x = 0)
October 8, 2016

Social Sudies
fishing if the ^%$&* feds would let you fish.
October 8, 2016

physics
I do not see the figure but am at a loss to understand how the ledge has anything to do with it unless he hits it. u = 17 m/s until splash Vi = 0 h = 7.9 m h = 4.9 t^2 so t = 1.27 seconds v = 9.81 t = 9.81*1.27 = 12.5 m/s speed = sqrt (17^2 + 12.5^2)
October 8, 2016

precalculus
T = 3 so f = 1/T = .333 Hz omega = 2 pi f = 2.09 radians/s at t = t0, d = -10 Amplitude = 10 d = -10 cos [ omega (t - t0) ] that is -10 when t = t0
October 8, 2016

Marbles
26 in bag both times 10/26 * 7/26
October 8, 2016

Stats
http://davidmlane.com/hyperstat/z_table.html
October 8, 2016

physics
5*4*4 = 80 6*3*3 = 54
October 7, 2016

Calculus - Approximation
y = x^(1/3) dy/dx = (1/3) x^-(2/3) at x = 1, y = 1 and dy/dx = (1/3)=m y = 1 + (1/3) (x-1) y = (1/3) x + 2/3 at x = 1.1 y = (1/3)(1.1) + 2/3 y = (1/3) 3.1
October 7, 2016

physics
north speed = Vn = 150 cos 35 east speed = Ve = 150 sin 35 + 26 speed = sqrt (Vn^2+Ve^2) heading = tan-1(Ve/Vn)
October 7, 2016

huh?
If you are a multiple of ten you are not a prime number. 30 = 3 * 2 * 5
October 7, 2016

Units?
130 POUNDS and 49 kg ? I think not
October 7, 2016

Physics
PE = m g h same m so same gh h = (9.8/3.7)5 in feet
October 6, 2016

Physics
Well, sort of, but in fact momentum is not conserved in this collision. The first law, conservation of momentum, applies ONLY if there is no external force. That is not the case here. The ground exerts a FORCE on the ball, changing its momentum from +mv to -mv Force = rate of ...
October 6, 2016

physics
call mass m and not 13.9 to save work, it cancels (1/2) m v^2 = retarding force * d (1/2)m v^2 = .122 m g d (1/2)(1.81)^2 = .122(9.81) d solve for d
October 6, 2016

Calculus 1
I suspect a square A = L w L + w = constant = k L = k - w so A = (k-w)w = k w - w^2 dA/dw = k - 2w = 0 for max or min so w = k/2 or w = k = k/2 sure enough a square so 1200/4 = 300 = L = w A = 90,000
October 6, 2016

Physics
pressure = rho g h = 1000 kg/m^3 * 9.81 * 1.2 Force = pressure * area = 1000 * 9.81 *1.2 * .8 /(10,000)
October 6, 2016

math
360/6 = 60 If there are 6 outside there are 6 inside. You probably want an even number so each has a mate opposite and you want 360/n to be a whole number.
October 6, 2016

Statistics
http://davidmlane.com/hyperstat/z_table.html
October 6, 2016

Algebra
-4.5 x - 2 y = -12.15 3.25 x - 1 y = -0.75 mult by 2 -4.5 x - 2 y = -12.15 6.50 x - 2 y = -1.50 ---------------------subtract -11 x + 0 = -10.65 so x = 10.65/11 etc
October 6, 2016

Physics
m g h same g same h (17.3 / 84.7) 2*10^3
October 5, 2016

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