Monday
February 8, 2016

# Posts by Damon

Total # Posts: 25,155

math multiply binomials by trinomials ( really need help)
well, we do not need the distributive property if you know FOIL I do not dare to do a) because I do not know if you mean (1/5)x or 1/(5x) when you write 1/5x b) (2a-3)(2a-3) = 4 a^2 - 12 a + 9 -(3a+4)(3a-4)= -9 a^2 + 0 a +16 2(3a+1)(3a+1)= 18a^2 + 12 a + 2 add 13 a^2 + 27 etc
January 17, 2016

Physics pleasse use ^
Ms = 2.13 * 10^5 Me Me = Me Ms x = Me (d-x) x/(d-x) = Me/Ms = 1/ (2.13*10^5) x<<<< d so assume x/d = 1/(2.13*10^5) x = 7.87 *10^8/(2.13*10^5) x = 3.69 * 10^3 = 3690 km check 3690 is indeed <<<< 7870*10^5 :)
January 17, 2016

Science Help
The number of molecules and their mass does not change however the volume increases if the balloon expands so mass/ volume decreases
January 17, 2016

algebra
F = k * w * v^2 /R 182 = k (1800) (900)/600 k = .0674 F = .0674 (1800) (2025)/650 = 378 pounds
January 17, 2016

math
3/8 + 1/3 = 9/24 + 8/24 = 17/24 24/24 - 17/24 = 7/24 but are you sure you did not spend 1/3 OF THE REMAINDER on snacks?
January 17, 2016

Calculus/ Application Of Derivative
I get A = pi r^2 = 75 pi r = 5 sqrt 3 so dV = pi (75) dh dV/dt = 75 pi dh/dt so dh/dt = .5 m^3/min / (75 pi m^2) .5/(75 pi) = .00212 m/min
January 17, 2016

Calculus/ Application Of Derivative
http://www.jiskha.com/display.cgi?id=1453063814#1453063814.1453064668
January 17, 2016

scroll down
I JUST DID THIS !!!
January 17, 2016

algebra
d = k t^2 64 = k (2)^2 so k = 64/4 = 16 then d = 16 (15)^2 d = 16 * 225 d = 3600 feet ============ check g = 32 ft/s^2 h = (1/2) g t^2 = 16 t^2 yes
January 17, 2016

History
We seem to be talking about the era of Cyrus etc well, back then most religions had gods for just about everything.
January 17, 2016

algebra 2
we want 10 y in both so mutiply the whole first equation by 2 -12 x + 10 y = +8 +7 x - 10 y = -8 -----------------------add - 5 x = 0 well, x = 0 then 5 y = 4 so y = 4/5 or -10 y = -8 so again y = 4/5 (that was a check) the lines intersect at (0 , 4/5 )
January 17, 2016

Maths
Trick: at depth h the volume increase with delta h = the surface area * delta h draw that and remember it. surface area = pi r^2 what is r of surface at h = 5 ? that takes some geometry triangle from center 5^2 + r^2 = 10^2 r^2 = 75 r = 5 sqrt 3 so dV = pi (75) dh dV/dt = 75 ...
January 17, 2016

I do not know
rounding to what? nearest whole number (4,3) to one decimal place? ( 4.3 , 3.3 ) to two places (4.35 , 3.33) etc etc etc
January 17, 2016

Math
(0,0) is the origin. I do not know where you drew it on your piece of paper :) (it might be way over on the lower left :)
January 17, 2016

math
b/g = 8/7 so b = (8/7) g b + g = 195 (8/7) g + (7/7) g = 195 15 g = 7 * 195 g = 7 * 195 / 15 etc
January 17, 2016

what?
I can not figure out what you mean. y = 6 * 4^2x + 2 or y = 6 * 4^(2x + 2) or y = 6 * 4^2 * x + 2 or y = 6 * 4^2 * (x + 2) and none of the above ca be expressed as y = A b x as far as I know
January 17, 2016

Physics
The horizontal speed of the supplies during the fall is the airplane speed (if you drop a bomb, then turn, because if you go straight it hits under you :) so how long to fall 160 meters? (1/2) g t^2 = 60 t^2 = 120/g = 120/9.81 t = 3.5 seconds
January 17, 2016

heat depends how far vertically down the ramp d sin theta
January 17, 2016

total cost ? = 1200 = 2 * 600 so q = 600 ? Total revenue? = 3 q = 1800 ?? Makes no sense Perhaps cost = 1,200 PLUS 2 Q ???
January 17, 2016

for what
6 a + 3 c = what is the question
January 17, 2016

physics
According to the de Broglie hypothesis, every object in the universe is a wave, a situation which gives rise to this phenomenon. The position of the particle is described by a wave function \Psi(x,t). The time-independent wave function of a single-moded plane wave of ...
January 17, 2016

physics
Look here maybe: http://en.wikipedia.org/wiki/Uncertainty_principle particularly the wave probability stuff.
January 17, 2016

physics
If you are into modern physics, there is a low but finite possibility of anything. In fact you might not be there where you think you are at all. Luckily you usually are on the same side of the wall you were before you did not move.
January 17, 2016

Math
Yes 80 gal * (8 pints/gal ) = 640 pints
January 17, 2016

Math
80 gallons is indeed more than 350 pints
January 17, 2016

Math
2/9 boys b 7/9 girls g b = (2/7) g or g = (7/2) b g - 250 = b (7/2) b - b = 250 (5/2) b = 250 5 b = 500 b = 100
January 17, 2016

Math link to sinking fund formula
for example http://www.math.utep.edu/Faculty/cmmundy/Math%201320/Worksheets/Sinking%20Funds%20&%20Annuities.pdf
January 17, 2016

Math
.052/4 = .013 = r so multiply by 1.013 every quarter year n = number of quarter years Google amount of a sinking fund S = 250 [(1+r)^n - 1 ] /r 6500 /250 = 26 = [(1+r)^n - 1 ] /r 26 = [ 1.013^n - 1 ]/.013 .338 = 1.013^n - 1 1.338 = 1.013^n so n log 1.013 = log 1.338 n (....
January 17, 2016

Math
Yes :)
January 17, 2016

Math
NO!!!! the whole point of my reply was .625 < .626
January 17, 2016

Math
but 5/8 = .625
January 17, 2016

Maths lit, geography ,agricultural science. Life science
How is a retired physicist in the United States supposed to be able to help with this? You must talk to the guidance person in your own school in your own country and follow your own wishes, not mine. If you have a math or physics problem, that is another matter :)
January 17, 2016

math,eng,phy,chem,bio,geography,economics
You used 8.99 - 3.65 = 5.34 g O2 for 8.99 g of Sc 5.34 + 8.99 = 14.33 g total Sc2O3 5.34 / 14.33 = .373 or 37.3 % ============================ check O3 = 3 * 16 = 48 Sc2 = 2 * 45 = 90 total molecular mass = 138 48/138 = .347 or 34.7 % looks like the experiment was a little off :)
January 17, 2016

sorry, do not understand experiment
What is the reaction you mean?
January 17, 2016

Physics
together we make 7+5 = 12 opposite we make 5-7 = -2
January 17, 2016

Calculus
eeewww http://www.wolframalpha.com/input/?i=plot+%282+%E2%88%92+x%29^%28e^%E2%88%92x%29+
January 17, 2016

World history/ Latin America
5. Phillipines ????? where are they?
January 17, 2016

World history/ Latin America
2. NO !!!!!
January 17, 2016

physics
F = k Q1 Q2/d^2 for each we want x so F = 0 distances are x and from 2.4 and 1-x from -5.6 for F = 0 2.4/x^2 - 5.6/(1-x)^2 = 0 (NOTE - by inspection you can see that to get zero you must be left of the origin, negative x) if you locate so F = 0, then the electric field from ...
January 17, 2016

Physics
hen eggs have reasonable sigma. classroom chalk (I assume we are talking used chalk) has wild variation so would require far more observations and might eventually converge to a mean weight somewhat over half the weight new in the box.
January 17, 2016

Physics
vertical problem: s = muzzle velocity Vi = s sin 30 = s/2 u = s cos 30 = .866 s 7.8 = .866 s t where t is time in the air so s t = 9 t = 9/s h = Hi + Vi t -4.9 t^2 at ground h = Hi = 0 0 = 0 + (9)/2) - 4.9 (81/s^2) 4.5 = 396.9/s^2 s = 9.39 m/s Now you do all that for new s = 1...
January 17, 2016

Math Teacher Certification Exam
B = .02 + 2 (6.24) = .02 + 12.48 = 12.50 12.50 + 6.24 = \$ 18.74 But beware. I am not certified to teach anything bur sailing!
January 17, 2016

Math/ algebra
area = A A/2 = pink Tulips (3/8) A = purple iris A/2 -(3/8) A = (1/8) A left (1/2)(1/8) A = 1/16 A = left so we want 1/16 You did fine (1/16)* 100 = 6.25 %
January 17, 2016

Physics
1.9 * 10^6 = 19 * 10^5 divide that by 1.7 * 10^5 the 10^5 cancels and the ratio of distance between to diameter is 19/1.7
January 17, 2016

Physics
19/1.7 = 11.2 11.2 * 26 = 290 cm = 2.9 meters
January 17, 2016

world history
agree, agree although oversimplified
January 17, 2016

world history
8. Is Taft 7. is income tax enough already, read this: http://quizlet.com/59801627/chapter-8-history-test-flash-cards/
January 17, 2016

Physics
.020 Cc (200 - T) = (.060 Cc + .050*4200) (T-30) where Cc is specific heat of copper in J/kg deg C
January 17, 2016

trigo
antenna height = h from roof up building height = b tan 42 10 = b/36 solve for b then tan 51 23 = (b+h) / 36
January 17, 2016

math
(.0025 /12)210,000 = \$43.75
January 17, 2016

math
Hey, if you have a calculator, divide. If you do not, google calculator. Oh well 2/9 is much less than 4.4/9 which is 1/2 4/7 is bigger than 3.5/7 which is 1/2
January 17, 2016

math
0.85 * x = 45 so x = 45 / 0.85
January 17, 2016

Calculus,Stationary Points,First derivative test
You say dy/dx = 6(x^2 - x - 2) so the function is horizontal when (x-2)(x+1) = 0 or x = 2 and x = -1 Agreed NOW you can test it like you did, but usually what you do is take the second derivative. If it is +, the function is at the bottom and about to start up. If it is ...
January 17, 2016

Maths
Hey, try I will do D 3 sqrt 18 = 3 sqrt (9*2) = 3 sqrt (3*3*2) = 3*3 sqrt 2 = 9 sqrt 2 = 9 (1.414) around 12.5 or so which is between 12 and 13 NOW check that with your calculator (Google calculator if you do not have one on your desk) 3 sqrt(18) = 12.728
January 17, 2016

ah I do not think so !
8+3+5 = 16 not 11 so 3/16
January 17, 2016

chemistry
25 + 273 = 298 degrees Kelvin P V = n R T n and R are constant You do not mention P, so I guess maybe the pressure is constant? V/T = n R/P = constant so V1/T1 = V2/T2 T2 = (V2/V1) T1 T2 = .5 T1 = 298/2 = 149 K -273 + 149 = - 124 C That is wicked chilly.
January 17, 2016

physics
DRAW A PICTURE The way I am looking at it: speaker at x = -6 speaker at x = +6 wave from left at x = -6 moves right y = sin (w t - 2 pi x/L) wave from right at x = + 6 moves left y = sin (w t + 2 pi x/L) at x y=sin(wt-2pi x/L)+sin(wt+2pi x/L) = 2sin(wt)*cos(2 pi x/L) This is ...
January 17, 2016

algebra ,
ends in 5 or 0 odd, so ends in 5 100 a + 10 b + c We know c = 5 100 a + 10 b + 5 a b 5 = 15 or a b = 3 a + b <5 100a + 10 b < 144 so a = 1 since a b = 3, b = 3 so 135
January 17, 2016

GCU
Well, it does not, but anyway W = k * L 162 = k * 9 k = 162/9 then W = k * 8 W = (162/9) 8 W = 144 Problem is, unlike in math class, when you make a boat longer you have to make it stronger and wider and deeper so in real life it is closer to W = k * L^3
January 17, 2016

Physics
heat the ball warms up and the ground warms up, but not much :)
January 17, 2016

geometry
You are welcome.
January 16, 2016

geometry
there are 360 degrees in a circle there are 2 pi radians in a circle therefore: multiply radians by (180 deg/pi radians) to get degrees :)
January 16, 2016

Mathematics
dy/dx = [x^4 e^x - 4 x^3 e^x]/x^8 = [ x e^x - 4 e^x ] / x^5 = 0 when x = 4 increasing if x>4 decreasing if x <4 what is sign of second derivative? It is a pain to compute, sketch graph of slope' http://www.wolframalpha.com/input/?i=plot+[+x+e^x+-+4+e^x+]+%2F+x^5 sure...
January 16, 2016

Math
do you mean y = e^rx ? r^2 e^rx + 5 r e^rx + 6 e^rx = 0 r%2 + 5 r + 6 = 0 (r+3)(r+2) = 0 r = -3 or -2
January 16, 2016

World History
The wrong ones are so terribly, horribly wrong and the right one is horribly correct :(
January 16, 2016

Math Terminology
3 , 2 , and 7 are constants
January 16, 2016

Algebra/math
It is not possible for you to copy and paste to this site. Therefore we do not see your origimi.
January 16, 2016

same gibberish. Read what you typed
January 16, 2016

Math
.1 * 23 = 2.3 half of that = 1.2 sum = 3.5 so I agree
January 16, 2016

gibberish
7000 days? 18 months? what are you talking about? anyway .05/12 = .004167 so every month multiply by 1.004167 so in twelve months v = Vi (1.004167)^12 v = Vi * 1.0511 or 5.11 percent annual interst
January 16, 2016

TYPO muzzle speed far too low to ever work, wrong.
Vi = initial up speed = ? cos A u = constant horizontal component = ? sin A s = horizontal airplane speed=340 T = flight time for both horizontal problem: 340 T = u T = ? T sin A so sin A = 340/(? ) which is kind of obvious :) now the vertical problem: h = 0 + Vi t -.49 t^2
January 16, 2016

math
v = 12,500 * .85^n
January 16, 2016

math TYPO
do you mean 40 cm^2 ? I will assume so A = (1/2) b h since it is 90 degrees, h is altitude , other leg 4 h = 40 h = 10 cm so we still need the hypotenuse c^2 = h^2 + b^2 = 100 + 64 = 164 = c = 2 sqrt (41) = 12.8 cm
January 16, 2016

Math
Lemme see 9 + 16 = 25 sure enough 2.5 * 9 + 3.25 * 16 = 74.5 which you could have done. If you are stuck, ask for help. If you need an answer checked, first check it.
January 16, 2016

yes 30 + 75 + 75 = 180 You choice is ok the rest are not 7 and 13 will not reach 22 6 12 18 is a straight line again 13 + 8 = 21, will not reach
January 15, 2016

Math
3 + 16/25 = 3.64 3.64 * 100 = 364 yes, agree
January 15, 2016

Geometry
No, I can not explain that because I agree with you either by side angle side or as you said by the angles
January 15, 2016

Mechanics(Ms.Sue)
efficiency is maximum 100%, and that is impossible. Output less than input D is correct Yes !!! for speed you need a speedometer for velocity you need a speedometer AND a compass speed = scalar velocity = vector
January 15, 2016

Math
try 1600/75
January 15, 2016

Math
You do not get 85 if you divide 17 miles / 20 minutes You get 0.85 miles/minute mph is wrong here. Hours is not in the problem
January 15, 2016

Careful !!
2. x/5 + 6 = 10 a) 44 b) 30 <----------- c) 20 d) –20 ======================= x/5 = 4 x = 5 * 4 x = 20 I do not have time to look at all of them but for heavens sake try checking by substituting back in using x = 20 x/5 + 6 = 10 20/5 + 6 = 10 ? 4 + 6 = 10 YES - I got ...
January 15, 2016

well, 36 = 6^2 so try x^2 + b x + 36 = (x+6)^2 x^2 + b x + 36 = x^2 + 12 x + 36 so x^2 + 12 x + 36 ------------------- more officially (b/2)^2 = 36 b/2 = 6 b = 12
January 15, 2016

Math
150,000 \$/sec * t sec = 3,000,000 t = 3,000 / 150 t = 20 seconds Again, nothing about minutes here, all is in seconds Of course we happen to know that 20 seconds is 1/3 of a minute :)
January 15, 2016

Math
4,500,000 /30 = 150,000 No, there is nothing about minutes in this problem
January 15, 2016

Math help plz!!
Look, I get 676 people. That is not on your list. Either you have a typo or your book does or I am stark raving mad.
January 15, 2016

Typo maybe?
1/3 * 1092 = 364 2/7 * 1092 = 312 364 + 312 = 676
January 15, 2016

Math
Now #10 10. –3p > –48 a) p < 16 b) p > –51 c) p < –16 <------------ d) p > 16 ====================== –3p > –48 divide both sides by -3. When you multiply or divide by a negative, REVERSE the arrow p < 16 WHICH IS A I do not...
January 15, 2016

Math
Oh all right, number 1 YOU SAY B ? 1. –9x – 5 = –95 a) 17 b) 11 <--------------- c) 10 d) –10 ===let me see =========== - 9 x - 5 = - 95 add 5 to both sides - 9 x = - 90 multiply both sides by -1 9 x = 90 divide both sides by 9 x = 10 which is not 11
January 15, 2016

history
January 15, 2016

GOT IT ????
That is important.
January 15, 2016

Algebra
f(x+h) = 4(x+h)^2 + 9 f(x) = 4 x^2 + 9 -----------------subtract delta y =4[x^2 + 2 x h + h^2 -x^2] = 4 (2 x h + h^2) delta x = h so delta y/delta x = 4(2x + h) END OF YOUR PROBLEM Oh my look what we have here as h ---> 0 !! delta y/delta x --> 4 (2x) That is called the ...
January 15, 2016

Algebra
Oh, I do not know what your belief means but I know what x+h and f(x+h) means. They are trying to lead you to calculus
January 15, 2016

Algebra
y(r) = 4 r^2 + 9 = u y(c) = 4 c^2 + 9 = g ----------------------subtract y(r)-y(c) = 4(r^2-c^2) = u-g =delta y delta x = (r-c) delta y/delta x = 4(r^2-c^2)/(r-c) = 4(r+c) I do not understand B
January 15, 2016

Math
5 * (n + 17 ) </= 25 so what is the problem? Just replace words with symbols.
January 15, 2016

MATH NEED HELP ASAP!!!!!
You said B I showed you that B is impossible.
January 15, 2016

MATH NEED HELP ASAP!!!!!
Hey in six years Henry's age will be H + 6 and Justin's age will be J + 6 so B simply is a non-starter
January 15, 2016

MATH NEED HELP ASAP!!!!!
So which one is your choice?
January 15, 2016

Science (physics)
P V = n R T n is proportional to number of gas molecules in the bag, remains constant here R is constant So P V/T is constant If T goes up, then P V goes up so likely the balloon gets bigger (stretches) and / or the pressure goes up
January 15, 2016