Tuesday
February 21, 2017

Posts by Damon

Total # Posts: 29,370

Science Physics
There is one thing you can really count on, Newton's First Law. If there is no external force on a system, the momentum remains CONSTANT Momentum before = Momentum after. If I could underline that PERIOD I would do so. You can not count on mechanical energy being the same ...
December 5, 2016

Math
w + L = 108 L = w + 30 so w + w + 30 = 108
December 4, 2016

physics
F = m a F = 3kg* 5m/s^2 = 15 Newtons a = F/m a = 15N/12.2kg a = 1.23 m/s^2
December 4, 2016

statistics
http://davidmlane.com/hyperstat/z_table.html
December 4, 2016

math double check please
yes, two 2s and a 3 yes, 420 * 3
December 4, 2016

pre calculus
http://www.jiskha.com/display.cgi?id=1480860809
December 4, 2016

Calculus
see the rope and the boat problem below.
December 4, 2016

Calculus
h height above bow (constant=7) y hor distance to bow (25 at moment) x = our rope length x^2 = h^2 + y^2 2 x dx = 0 + 2ydy dy/dx = x/y dy/dt = dy/dx dx/dt = 2 (x/y) x = sqrt (7^2 + 25^2) = 26 so dy/dt = 2 (26/25) = 2.08 m/s
December 4, 2016

Calculus
hint dA = 2 pi r dr so dA/dr = 2 pi r and dA/dt = dA/dr * dr/dt
December 4, 2016

PHYSICS (REALLY DIFFICULT PLEASE HELP)
18+273 = 291 K 0 + 273 = 273 K P V = n R T 103 * 23 = n R *291 n R = 103*23/291 same n R later 101 V = n R 273 V = n R (273/101cm^3) V = (103*23/291)(273/101) cm^3 22 cm^3 = .0022 Liters = 22*10^-6m^3 ================================== P V = n R T 101325 (22.4 liters)(1m^3/...
December 4, 2016

Sequence and serice
54/100 or 27/50 a rational number is any one that can be expressed as a ratio of whole numbers.
December 4, 2016

maths
2n + 24/6 = 25/6 n = 1/12
December 4, 2016

pre calculus
2 1 2 4 2 2 0 5 2-1 6 2 1 0 2 3/2 0 1-2 1 0 0 0 0 (3/2, 1, 0)
December 4, 2016

pre calculus
http://www.gregthatcher.com/Mathematics/GaussJordan.aspx
December 4, 2016

Maths
The diagonal sqrt(24^2 + 18^2)
December 4, 2016

Where are you stuck?
So what did you do?
December 3, 2016

Math
(1/2)(40 + 3/8) = 20 + 3/16 20 3/16
December 3, 2016

Math
2/12 = 1/6 24 * 1/6 = 4 or 12/24 = 2/x 12 x = 48 x = 4 or the original width was twice the length twice 2 is 4
December 3, 2016

Math
Then count the number of one inch by one inch square boxes. You will get 50 of them, 5 times 10 :)
December 3, 2016

Math
Because to find the area of a rectangle you multiply the length by the width. To figure out why, draw a picture 10 inches by 5 inches and divide it up into columns one inch wide and rows inch high.
December 3, 2016

Math
yes, multiply
December 3, 2016

CSC
(2s-44)+(s+22)+ s = 5858 4 s -22 = 5858 4 s = 5880 s = 1470 etc
December 3, 2016

Physics
vertical problem Vi = 25.8 sin 20 = 8.824 m/s v = Vi - 9.81 t at top v = 0 t = 8.824/9.81 = .900 seconds at top (therefore 1.8 seconds in air by the way) h = Vi t - (9.81/2) t^2 = 8.824(.9) - 4.9(.81) = 7.94 - 3.97 = 3.97 meters high horizontal problem u = 25.8 cos 20 = 24.2 ...
December 3, 2016

Math
multiplying by 5/2 should not give the same answer as multiplying by 2/5(which is dividing by 5/2)
December 3, 2016

Math
21 7/8 * 2 1/2 one way is to use distributive property (21 + 7/8)(2 + 1/2) =(2 + 1/2)(21) +(2 + 1/2)(7/8) = 42 + 21/2 + 7/4 + 7/16 = 42 + 168/16 + 28/16 + 7/16 = 42 + 203/16 = 42 + 12 + 11/16 = 54 11/16
December 3, 2016

Physics
yes,your table is for a = dv/dt = 4 so dv = 4 * dt dv/dt = a = 4 v = a t = 4 t x = (1/2) a t^2 t a v x 0 4 0 0 1 4 4 2 2 4 8 8 3 4 12 18 4 4 16 32 5 4 20 50 It is that v column you want, how far it moves PER SECOND not how far it moved total.
December 3, 2016

Physics
so dx/dt = a t dx = a t dt at t = 0, dx = 0 at t = 1, dx = a at t = 2, dx = 2a at t = 3, dx = 3a at t = 4, dx = 4a etc in other words you are looking at v(t), the velocity, which is linear with time (the CHANGE in position, not the position) v = a t the POSITION itself will be...
December 3, 2016

College Calc
sqrt 576 = 24 24*4 = 96
December 3, 2016

College Calc
LOL,square min P, given A A = L w so L = A/w P =2L+2w P = 2A/w + 2 w 2 w^2 - w P = -2 A w^2 -(P/2)w = A w^2 -P/2 w + P^2/16 = -A + P^2/16 (w-P/4)^2 = -(1/16)(16A-P^2) vertex when w = P/4 (that is a square :) Area = P^2/16 = (P/4)^2 of course P given, max A A = L w P =2L+2w so ...
December 3, 2016

Physics
R is speed of rain r is angle of rain to vertical horizontal rain we see = Rsinr+bike speed vertical rain we see = R cos r case 1 hor = R sin r + 20 ver = R cos r tan 45 = (R sin r +20) /Rcos r case 2 tan 19deg48 min = (R sinr +12)/R cos r
December 3, 2016

Algebra
It is as if she got 89 on 5 of the 6 tests! (89*5 + x)/6
December 3, 2016

Physics
http://formulas.tutorvista.com/physics/doppler-shift-formula.html
December 3, 2016

Physics
As the ambulance approaches, the pedestrian will hear a higher frequency. As it recedes a lower frequency. Add the absolute values of the changes. For the formula, Google Doppler shift (classical not relativistic)
December 3, 2016

chemistry
4/2 = 2 mols of CO2 for every mol of C2H6 mol of C2H6 = 2*12+6 = 30 g mol of CO2 = 12+32 = 44 g 7500 * 2 * 44/30
December 3, 2016

history knowledge
I guess I would have to go along with that but wonder if it would have lasted if he had lived. The last few years of scooting around the Middle East and western Asia did not seem to be aimed at establishing any sort of permanent government but rather putting people in titular ...
December 3, 2016

Physics
Fup = m (9.81 + v^2/R) 2*265 = 30 (9.81+v^2/1.4) (b) 2*265 up assuming the seat has no mass :)
December 3, 2016

Math
55% is Cu and FE so 45% is zinc .45 *720 = 324 grams That is assuming this is a MATH, not a Chemistry problem. If it were Chemistry they might be looking at 1/4 of the molecules are Cu, not 1/4 of the mass.
December 3, 2016

Math
2^n
December 2, 2016

Math
5(.07)(8000)=2800
December 2, 2016

Calculus
Yes, of course -4-1 = -5 :)
December 2, 2016

Calculus
where do they hit? 4 x^2 = 45 - x^2 x^2 = 9 x = +/- 3 cylinder height = 45-x^2 - 4 x^2 = 45 - 5 x^2 cylinder thickness = dx cylinder circumference = 2 pi x so V=?[0,3]2 pi x(45-5x^2)dx
December 2, 2016

So what?
no question is asked.
December 2, 2016

physics
Vertical problem: at max height (half the trip) 600 = Vi t - .5*9.8 t^2 .5*9.8 t^2 - Vi t + 600 = 0 also v = 0 so 0 = Vi -gt t = Vi/g = Vi/9.8 so .5*9.8(Vi^2/9.8^2) - Vi^2/9.8 +600 = 0 600 = .5*VI^2/9.8 Vi = 108 m/s initial up speed t = rising time = 108/9.8 = 11.1 s total ...
December 2, 2016

Finite Math
A (1.0465)^6 = 15,000 A = 15,000/1.313516 = 11,419.73
December 2, 2016

physics
Ke = (1/2)(1260)(14.8^2) Joules go ahead and integrate m a dx if you want but energy is a lot easier.
December 2, 2016

Physics
total weight = (251+350)(9.81) + rhogas 9.81(4/3) pi (9.5)^3 where rhogas is the mass per unit volume of the gas in the balloon weight must = weight of air displaced = rhoout g (4/3)pi(9.5)^3 rho gas = kg/mol * n = .029 n where n is mols in PV =nRT T = 273 + T that we want rho...
December 2, 2016

Pressure in Physics
60 *9.81/10 N/m^2 or Pascals if you mean on the floor on earth and 10 is the floor area
December 2, 2016

maths
2 pi Ro = 44 solve for Ro then Ri = Ro - 2 so inner circumference = 2 pi Ri and Path area = pi(Ro^2-Ri^2)
December 2, 2016

math
16 = 4*4 12 =4*3 so 4*4*3 is LCM = 48 of each 3 packs HD 4 packs buns
December 2, 2016

Physics
google Bernoulli constant= v^2/2 + g z + p/rho in your units v in m/s p in Pascals(N/m^2) rho = 1000 kg/m^3 for water g about 9.8 v at bottom = 1.2 m/s v at top = 2 v at bottom =2.4 m/s z at top = z at bottom + .2 meters p/rho bottom =143000/1000 so 2.4^2/2 + 9.8(.2)+ 143 = 1....
December 2, 2016

Math
B yes C 128(0.5)^3 128*.125 = 16 yes D 128*.5^8 = 128* .00390525 = 0.5 YES !!!!!
December 1, 2016

Math
Gabby drove t-3 hours she drove 2 hours so t-3 = 2 and Ryan drove 5 hours D = Ryan speed * 5 D = Gabby speed * 2 so 5 R = 2 G but G = R+42 so 5 R = 2(R+42) 3 R = 84 R = 84/3 = 28 HUY - The DIFFERENCE is 42
December 1, 2016

Calculus 1
v = x^3 dv/dx = 3 x^2 dv/dt = dx/dt * dv/dx dv/dt = 4 * 3(121) cm^3/s
December 1, 2016

math
1000-850 = 150 interest 150 = 850 (.08) t
December 1, 2016

Pre-Calculus
satellite position is likely to be x, y , z of t :)
November 30, 2016

science
1. I disagree with you. People just assumed we were at the center. Partly religious 2. agree 3. agree 4. I agree with you. A and B are obvious. D is the sun and moon working together to produce spring tides when the moon is full and new and neap tides when the moon s half moon...
November 30, 2016

Algebra
v = dh/dt = 32 -32 t at top, v = 0 t = 1 h = 9+16 = 25 ====================== now with algebra 16 t^2 -32 t =9 - h complete square t^2 -2 t = (-1/16)(h - 9) t^2-2t+1 = (-1/16)(h - 9)+16/16 (t-1)^2 = -(1/16)( h-25) t = 1, h=25 same answer
November 30, 2016

precalculus
1 x +1 y = 2 1 x +1 y = 3 1 1 2 1 1 3 subtract top one from this 1 1 2 0 0 1 oh my! 0x+0y=1 ?
November 30, 2016

College alegbra
I assume this does not mean the perimeter but the total length of fencing. I assume x is the length and there are 3 y fences P = 2 x + 3 y x y = 1500 so y = 1500/x then P = 2 x + 4500/x x P = 2 x^2 + 4500 2 x^2 - xP = -4500 x^2 -xP/2 = -2250 x^2 -xP/2 + P^2/16 = -2250 + P^2/16...
November 30, 2016

Calculus
the function climbs uphill 15 from -3 to +12 in its jaunt of +5 from -1 to +4 that means that somewhere in between there the slope of the function is slope = 15/5 = 3 so at some x = c between x = -1 and x=+4slope = f'(c) = 3 so a)
November 30, 2016

Physics
(1/2) m v^2 = m g h or use Bernoulli (1/2) rho v^2 + rho g h + P = constant here P = 1 atm on top of the tank and at the outflow so the two ways are the same v = sqrt (2 g h ), just like the water fell amount that comes out per second = Q = Area*v = pi r^2 v = pi*10^-4 v so Q...
November 30, 2016

Physics
F/m = 2/60
November 30, 2016

physics
a = F/1 = i + 2 j -2 k v = Vi + a t x = Xi + Vi t + (1/2)a t^2 v at 5 = i+0j+2k + 5i +10j -10k = 6i + 10j - 8k x at 5, well assume start at (0,0,0) x = 0 +(i+0j+2k)5 +(1/2)(i + 2 j -2 k)25 = 5i+0j+10k+(1/2)(25i+50j-50k) =17.5 i +25 j -15 k check my arithmetic !
November 30, 2016

Physics
yes, both in watts or Joules/second
November 30, 2016

Math
same as when tan = -1 which is when theta = 90+45 =135 = 3 pi/4 or when theta = 360 - 45 = 315 = 7 pi/4
November 30, 2016

Physics
m v^2/r = 50 * 64 / 8 = 400 m/s^2
November 30, 2016

Calculus AB
-(x^4 - 5 x^2 + 6) / (x +3^.5) -(x^2-3)(x^2-2) /(x+3^.5) OH LOOK! -(x-3^.5)(x+3^.5)(x^2-2)/(x+3^.5) = -(x-3^.5)(x^2-2) when x is -3^.5 = -(-2*3^.5)(1) = 2 sqrt 3 Now there is a limit and I am at it without you doing some.
November 30, 2016

Calculus
is x^(1/5) defined and continuous in that interval? (-1)^(1/5) = -1 etc, seems ok how about arc cos x that looks fine x/(x-3) woukld blow up at x = 3, but we do not go there so it is ok but Oh my, sqrt(-1) is imaginary! and is called i for want of a real number to use. It is a...
November 30, 2016

Integral Calculus
Height = sin x radius = (3 pi/2 -x) = r so dr=-dx d volume = sin x (2 pi r (-dr)) = 2 pi sin x (3pi/2-x)dx =2 pi(3pi/2) sin x dx - 2pixsin x dx = -3 pi^2 cos x - 2 pi [sinx-xcosx] = [-3 pi^2+2pix]cos x -2 pi sin x at pi - at 0 sin is 0 at both so cos pi = -1 so - [-3 pi^2+2pi^...
November 30, 2016

Algebra (Please Check My Answers)
4. James attached a diagonal brace across a rectangular frame that measures 6 feet by 8 feet. What is the length of the diagonal brace? ~ 2 feet ~ 10 feet ~ 14 feet ~ 48 feet*** =================== 36+64 = 100 sqrt(100) = 10
November 30, 2016

ss
I am inclined to think you made the correct guess.
November 30, 2016

Math
Hmm be sure to put the numbers back in to check. a = 20 and c = 10 13 + 3 = 16
November 30, 2016

Math
a = 2 c a-7 + c-7 = 16 2 c + c - 14 = 16 3c = 30 c = 10
November 30, 2016

Math
x+35 + 5x-21 =180
November 30, 2016

CHEM 1301
H = 8/3 *12.2 = 32.5 12.2 + 32.5 = 44.7
November 30, 2016

cal
Good :)
November 30, 2016

cal
g = (x-1)/(2x+4) dg/dx = [(2x+4)-2(x-1)]/(2x+4)^2 at x = -1 dg/dx = m the slope = [(-2+4)-2(-2)]/(2)^2 = 6/4 = 3/2 and g = -2/2 = -1 so y = m x + b -1 = 3/2 (-1) + b b = 1/2 so y = (3/2) x + 1/2 or 2 y = 3 x + 1 check my arithmetic!
November 30, 2016

cal typo ?
g = x -.5 x + 4 did you mean x^2 maybe? or what?
November 30, 2016

Algebra
4 a + 5.5 c = 92 a + c = 20 4 a + 5.5 c = 92 4 a + 4 c = 80 ------------------subtract 0 + 1.5 c = 12 c = 8 etc
November 30, 2016

math
maximize .085 x + .068 y x+y <= 50,000 x>=6,000 x<=27,000 y<=34,650 x+y>=1 phony to fill fields I get $3859 at (27000, 23000) ==================== http://www.wolframalpha.com/widget/widgetPopup.jsp?p=v&id=1e692c6f72587b2cbd3e7be018fd8960&title=Linear%...
November 30, 2016

cal
You are welcome.
November 30, 2016

cal
3 x^2 dx + 3 y^2 dy = 3 x dy + 3 y dx (y^2 -x)dy = -(x^2-y)dx dy/dx = - (x^2-y)/(y^2-x)
November 30, 2016

Math
56 = 2 * 28 = 2*2*14 = 2*2*2*7 can not have more than one 2 2*7 = 14
November 30, 2016

math
2 by 3/2
November 30, 2016

value
4/5 = .8
November 30, 2016

Math
+ C :)
November 30, 2016

Math
x - 6?xdx/( x^2+1) let z = x^2+1 dz = 2 x dx so x dx = (1/2)dz then x - 6?(1/2)dz/z x - 3 ln z x - 3 ln(x^2+1)
November 30, 2016

Math
?(x^2-6x+1)/(x^2+1) dx =?(x^2+1)dx/( x^2+1)-6?xdx/( x^2+1) = ?dx - 6?xdx/( x^2+1)
November 30, 2016

Portions and integers
Zero just gives you an arbitrary point on the number line to measure the other two points from. The fact that it happens to be the melting point of ice is irrelevant to this problem. -89 is colder than -39 -89 is LEFT of -39 on our number line -89 < -39 how much colder is ...
November 30, 2016

Not sure
skin, hair, nails the only thing listed that is related is the hand.
November 30, 2016

physics -- impossible
if r is the radius above earth center the speed is totally impossible. I suspect a typo
November 29, 2016

Huh initial height?
If the velocity is only 3 m/s at the bottom, no way it will go up 10 meters. Typo? Did you leave out an initial height?
November 29, 2016

math
2 x/5 + 35000 = 3 x/4 35000 = 15x/20 - 8x/20 = 7 x/20 5000 = x/20 x = 100,000
November 29, 2016

genetics - no idea
not my thing - need biology teacher
November 29, 2016

Physics
LOL valve straight down is stable (pendulum) valve straight up is unstable (balancing pencil on nose) I = mr^2 = 1.005(.36) (about .36) for angle x in radians, restoring moment is about .005*9.81 x r = .003*9.81 x oh well call g = 10 instead of 9.81 = .03 x .03x = -I alpha = -...
November 29, 2016

Algebra 2
74-m = m/2 + 11 63 = 3 m/2 m = 63*2/3 = 42 74 - 42 = 32
November 29, 2016

maths
yes
November 29, 2016

maths
250 - 80 = 170 girls (170/250)100 = ?
November 29, 2016

2
You can not row cotton profitably everywhere. You need the right soil and water conditions and preferably a large area of flat land. Rice in particular uses very different soil conditions, like wet. Virginia climate was very good for tobacco as was Ky and Tenn.
November 29, 2016

CHECK! LAST TIME MATH!
100% - 20% = 80% or .8 100% - 10% = 90%
November 29, 2016

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