Sunday
May 1, 2016

Posts by Damon

Total # Posts: 26,125

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
3. No
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
and also read my previous reply 5.11 %
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

Geometry(Check My Answers)
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

Quadratic Equation (math)
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
As Ms. Sue said, your answer depends on your point of view.
January 15, 2016

history
Not C
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

AP Physics 1
north = 21 - 26 = - 5 east = 16 distance = sart (5^2+16^2) on x y axis system tan h = -5/16 h = -17.35 so 17.35 degrees below x axis which is a compass bearing clockwise from north of 17.35 + 90 = 107.35 about ESE
January 15, 2016

Math
What is the experimental probability of rolling a 3? A.0.11 B.0.22 C.0.30 D.0.27 ================ 11/50 = 22/100 = .22
January 15, 2016

Math
I counted 3 out of 20 Yes, you have it
January 15, 2016

Math ASAP ASAP!!!!!
yes 80/.2 = 800/2 = 400
January 15, 2016

Geometry
9 inches * (1 foot / 12 inches ) = .75 foot so 5.75 / 2 = h/7 multiply both sides by 14 5.75 * 7 = 2 h h = 7.75 * 7/2 h = 27.125 which is 27 1/8 feet which is 27 feet 1 and 1/2 inches :)
January 15, 2016

Math
What is the y-intercept of y = 2/3x + 2? I have to write it out but how? ------------------------------ The y axis intercept is where x = 0 which in this case is 2 and I think you meant to type y = (2/3) x + 2 because what you typed was y = 2/(3x) + 2 think parentheses when ...
January 15, 2016

PHYSICS
Beats me, but if they go faster than light they can do about anything.
January 15, 2016

MATHS
log ( 2^3 * 20/1.6) log (8 * 20/1.6) log 100 log 10^2 2 log 10 if these are base 10 logs then log10 = 1 so 2*1 = 2
January 15, 2016

PHYSICS
a photon has momentum but not mass. I am not sure "accelerate" has any meaning in this context. Of course the speed of light can change in different materials and its direction can change, but I am not sure I would call that "acceleration" (rate of change ...
January 15, 2016

SCIENCE HELP PLS
P V = n R T n/V is a proportional to density (molecules per unit volume) n/V = P/RT so either the temp went way up or the pressure went down You can pick the decrease in pressure.
January 15, 2016

Algebra
http://www.jiskha.com/display.cgi?id=1452879533#1452879533.1452880085
January 15, 2016

Physics, and I just did it scroll down
see problem below this one.
January 15, 2016

Physics :)
Vi = 13 m/s Hi = 1.0 m h = Hi + Vi t - 4.9 t^2 0 = 1 + 13 t - 4.9 t^2 now it is algebra 4.9 t^2 - 13 t - 1 = 0 t = [ 13 +/- sqrt (169 + 19.6)/9.81 use positive time :) t = 2.73 seconds (good hit, wow ! )
January 15, 2016

united staes history
We did not call them "slaves". They were "crew".
January 15, 2016

Physics
F = 543 - 473 = 79 N down on the student mass of student = 543/g a = F/m = 79 / (543/9.81) = 1.43 m/s^2 down
January 15, 2016

Maths literacy and tourism,life science,geography
Hermit
January 15, 2016

Math
Moreover it is not c :)
January 15, 2016

ECE
well it asks for the "drop", not just the difference so I guess I would say it dropped 5 However the question is poorly worded.
January 15, 2016

Physics
initial ke = (1/2)89.5(5.7)^2 + (1/2)81.5(2.58)^2 final ke = (1/2) 171 (v)^2
January 14, 2016

Physics
LOL, they clung to each other after so after the crash the total mass is 89.5 + 81.5 = 171 kg now east, the fullback I call +x initial momentum = 89.5*5.7 - 81.5*2.58 = 431 kg m/s final momentum = 171*v Newton #1 say those are identical so 171 v = 431 v = 2.52 m/s
January 14, 2016

algebra
q(21) = 6 - 5*21
January 14, 2016

Math
(2j+1) / (j+1)^2 j^2 ??? (2j+1) / (j^2 + 2 j + 1)j^2 (2 j + 1) / (j^4 + 2 j^3 + j^2) (2 j + 1) / (j^2 + 2 j^3 + j^4) try 12 25/( 144 + 3456 + 20736)= 25/24336 = .001027 this is going to get small fast the denominator will be totally dominated by j^4 and what we really will ...
January 14, 2016

i need your help damon
12.5 ft (.5 in/2 ft) = 3.125 in 11.5 ft (.5 in/ 2 ft) = 2.875 in so 2*3.125 + 2*2.875 = 12 in
January 14, 2016

i need your help damon
first of all look at what I did a minute ago for someone else: http://www.jiskha.com/display.cgi?id=1452820078
January 14, 2016

physics
You did not say if your angle T is measured from across or from upstream. I will do it from across x - along walk y across walk Vc = cat running speed Vx = Vc sin T - .5 = 0 for result we want Vy = Vc cos T so 0 = 1 sin T - .5 sin T = .5 T = 30 degrees Vy = 1 cos 30 = .866 if ...
January 14, 2016

Conceptual Physics
learn to convert like a physicist (not math way) 106 mm * ( 1) does not change anything BUT I claim that 10 millimeters /1 centimeter) is ONE, because it is the same top and bottom so what I do is: 106 mm (1 cm/10 mm) = 10.6 cm mm cancel and left with cm and 106 mm (1 m/1000 ...
January 14, 2016

i really need help but dont know how to do it
I have a million people to help, look up and down :)
January 14, 2016

i really need help but dont know how to do it
3.25 in (1 ft/.25 in) = 13 ft 2.75 (1/.25) = 11 feet area = 13 * 11 = 143
January 14, 2016

Algebra
s^2 = (5x - 3)(5x - 3) = (5x-3)^2 so s = 5x-3 when in danger or in doubt: http://www.mathportal.org/calculators/polynomials-solvers/polynomial-roots-calculator.php
January 14, 2016

math
2 L + 2 w = 38 so L + w = 19 and L = 19-w w L = 90 w (19-w) = 90 w^2 -19 w + 90 = 0 (w-9)(w-10) = 0 9 by 10
January 14, 2016

geometry
41 1/3 / 2 1/3 = 124 / 7 = 17.7 yards^2 / gal 17.7 * 9 = 159 ft^2/gal 275 - 159 = 116 difference
January 14, 2016

Physics
sin w t + sin x t = 2 sin.5(w+x)t cos.5(w-x)t beat frequency is omega = 2 pi f = .5(w-x) assume gum decreases x thereby increasing w-x so w is our 200 Hz fork w = 200*2 pi = 400 pi radians/s w - x = 5*2 pi = 10 pi so x = 390 pi = 195 Hz I suppose that is more than you wanted ...
January 14, 2016

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