Friday

July 1, 2016
Total # Posts: 26,400

**where is your attempt?**

My job is not to just do it for you but to help if you get stuck.
*May 8, 2016*

**Calculus**

x^2(3y^2dy) + 2x dx(y^3) - 2ydy +xdy + dx y = 0 dy (3x^2y^2-2y +x) +dx(2xy^3+y)=0 dy (3-2+1) + dx (2+1) = 0 2 dy = -3dx m = slope = dy/dx = -3/2 so y = -3/2 x + b 1 = -3/2 + b b = 5/2 so y = -3/2 x + 5/2 or 2 y = -3 x + 5
*May 8, 2016*

**English**

Post means after.
*May 8, 2016*

**English**

disagree with #7 answer disagree with #11, ante means "before"
*May 8, 2016*

**science**

http://sciencelearn.org.nz/Contexts/Light-and-Sight/Teaching-and-Learning-Approaches/Investigating-refraction-and-spearfishing
*May 8, 2016*

**science**

Google Snell's law. They always show that particular picture :) Perhaps google spear fishing as well in the second question, something with the same color and index of refraction does not bend or reflect or anything and is invisible.
*May 8, 2016*

**calculus**

if Q = 100 = 10^2 r = (1/3)10^-3*10^6 or (1/3)(10^3) + (1/2)10^-2*10^4 or (1/2)(10^2) + 10^1*10^2 = 10^3 + 10^2 = about 333+ 50 + 1000 + 100 or about 1483 I get
*May 8, 2016*

**calculus**

Oh my Have you done integration of polynomials? integral x^n dx = 1/(n+1)x^(n+1) so integral x^2 dx = (1/3)x^3
*May 8, 2016*

**just integrate**

r = (1/3)(.001)Q^3 + (1/2)(.01)Q^2 + 10 Q + 100
*May 8, 2016*

**B**

dx/dt = 500 dc/dx = 0 + 2 x dc/dt = dc/dx * dx/dt = 2 x * 500 so at x = 6000 dc/dt = 12,000 * 500
*May 8, 2016*

**calculus**

1 ∫ (1+3x)^.5 dx 0 let z = (1+3x) dz = 3 dx so dx = (1/3)dz if x = 0, z = 1 if x = 1, z = 4 so 4 ∫ (z)^.5 dz/3 1 is (1/4.5) z^1.5 at z = 4 - at z = 1
*May 8, 2016*

**calculus**

well, one way: let z = 3 + 2x then dz = 2 dx so dx = (1/2)dz if x = 0, z = 3 if x = 2, z = 7 so 7 ∫ (5/z)(1/2) dz 3
*May 8, 2016*

**math**

o cups orange g cups ginger f cups filler o + g + f = 400 120 </= o </= 400 0 </= g </= 80 f </= 280
*May 8, 2016*

**math**

58 = 8 x + 9 (7-x) 58 = 8 x - 9 x + 63 x = 5
*May 8, 2016*

**math - hummm**

That depends :( If you do not put the grape back, you only have 31 in the machine when you draw the mango. You assumed the two events were independent. They may not be. I would have said: 10/32 * 16/31 not 32
*May 8, 2016*

**science**

H2SO4 ???? 4*6*10^23 O atoms per mol so 8 * 6 * 10^23 in two mol = 48*10^23 = 4.8 * 10^24 quite a few
*May 8, 2016*

**science**

Huh ? do you mean The measured density of He at STP is 0.1784g/l.what is the weight of one mole? If so then 1 mole = 22.4 liters at STP 22.4 * .1784 = answer
*May 8, 2016*

**science**

a mol of O2 has mass of about 32 g/mol so 32 g/mol * 1 liter/1.429 g = (32/1.429) liters/mol I hope it is about 22.4 liters :)
*May 8, 2016*

**physics**

ah --- if the altitude of the kicking foot and the goalie hands is the same, then the kinetic energy is the same. same (1/2) m v^2 so same 16 m/s (ignoring air friction)
*May 8, 2016*

**math**

yes, true
*May 8, 2016*

**Math**

7-2 = 5 so (5/7)x = 14 x = 14 * 7/5 total amount he had so cost = (2/7)(14 * 7/5) = 28/5 = $5.60 ==============check 14*7/5 - 28/5 = 10(7/5) = 14 yes
*May 8, 2016*

**physics**

How long to fall 54 meters with no initial vertical velocity? h = (1/2) g t^2 54 = 4.9 t^2 t = sqrt (54/4.9) then 130 = u t so u = 130/t
*May 8, 2016*

**science**

west =(1/3)hour*80 + (1/10)hr* 30 * cos 45 north = (1/10)*30 * sin 45 distance = sqrt(north^2+west^2) displacement = distance at angle T north of west where tan T = north/west speed = distance/ (1/3+1/10) velocity = speed at angle T
*May 7, 2016*

**calculus help**

You better use wolfram. That is a serious mess. http://www.wolframalpha.com/input/?i=integrate+dx%2F%283x^3-5%29^3+ type in integrate dx/(3x^3-5)^3 and click on the equal sign.
*May 7, 2016*

**Science**

distance d from home to college total distance = 2 d time to college = d/20 time to get back = d/40 total time driving = d/20 + d/40 average speed = 2d/(d/20+d/40) = 80/(2+1) = 80/3 = about 27 km/h
*May 7, 2016*

**Math**

pi (3.5)^2 (40) = 28 * 22 * h
*May 7, 2016*

**physics**

F = m a
*May 7, 2016*

**Math**

x = (3 y + 1) 4(3y+1) + 5 y = 4 12 y + 4 + 5 y = 4 17 y = 0 y = 0 x = 3*0 + 1 = 1 (1,0)
*May 6, 2016*

**Math**

m multiple pointers s short responders m + s = 20 3 m + 8 s = 100
*May 6, 2016*

**Geography can someone please help me NOT ms.sue**

I passed sixth grade.
*May 6, 2016*

**Geography can someone please help me NOT ms.sue**

It is all there in the Google stuff, political, economic and well I am not sure about socially. I have never been very social.
*May 6, 2016*

**Geography can someone please help me NOT ms.sue**

They named a beer after him.
*May 6, 2016*

**Geography can someone please help me NOT ms.sue**

http://www.google.com/search?q=stamp+act+unfair&ie=utf-8&oe=utf-8 You have got to be kidding.
*May 6, 2016*

**Geography can someone please help me NOT ms.sue**

That grouchy one in Massachusetts.
*May 6, 2016*

**MATH PLEASE HELP FAST**

1. 8 - 3 is NOT 11 but 5 what is 7+4? about 11 ? what is 1 - 3 maybe -2 look for f^2 + 11 f - 2 Now you do them more carefully
*May 6, 2016*

**Physics**

volume of water displaced = .1034^3 = .0011055 m^3 times density of water which is about 1000 kg/m^3 =1.106 kg of water displaced Archimedes says we can float that much mass .150 + m = 1.106 m = .956 kg = 956 grams
*May 5, 2016*

**Physics**

Why would surface area have anything to do with it?
*May 5, 2016*

**Physics**

diameter has nothing to do with it. rho g h = 1000 kg/m^3 * 9.81 * 30.34 Pascals
*May 5, 2016*

**trig, precalc, math, algebra, trigonometry**

cos theta = adjacent/hypotenuse call adjacent side v call hypotenuse 1 then cos theta = v opposite side = sqrt(1^2 - v^2) tan theta = sqrt(1-v^2) /v
*May 5, 2016*

**Physics**

If x is horizontal, there is no x component of weight. If x is down the slope then assuming you really mean 76 kg it is 76 * 9.81 * sin 10
*May 5, 2016*

**Algebra**

n and 2n-1 n + 2n - 1 = 20 3 n = 21
*May 5, 2016*

**Science**

I agree
*May 4, 2016*

**PHYSICS**

You push them to make them faster increasing their momentum. However they can not go a lot faster so that increased momentum shows up as mass rather than velocity. m = mo/sqrt (1 -v^2/c^2) as v ---> c the mass gets huge approaching undefined.
*May 4, 2016*

**Math**

x and x+5 x(x+5) = 6 x^2 + 5 x - 6 = 0 (x-1)(x+6) = 0 x = 1 or -6 if x = 1 x+5 = 6 and if x = -6 x+5 = -1
*May 4, 2016*

**Parametric Curve**

LOL e is a horizontal line, y = 5 b is a parabola, do what I suggested.
*May 4, 2016*

**Parametric Curve**

Well, I suppose if you do not see it as is, you can do x and y for example in (a) y = 4t-2 x = t+1 so t = x-1 y=4(x-2) - 2 y = 4 x -10 dx/dt=dy/dt = 0 so constant speed (d) If you do no see it is a circle, do the same thing again y = (2t+1) cos t y^2 = (2t+1)^2 cos^2 t x^2 = (...
*May 4, 2016*

**math nid this asap tyy**

m g h = (1/2) m v^2 h = v^2/2g v the same v^2 = 2 g h 2 * 9 .8 * 2.35 = 2 * 1.6 * h h = 14.4 meters
*May 4, 2016*

**PLEASE HELP WITH ALGEBRA**

You have 185 bands in the box pink 95/185 = 19/37 brown 90/185 = 18/37
*May 3, 2016*

**0 through 10 is 11 spaces**

10 equal sections from 0 to 10 ??? No, that is 11 1 to 10 would be ten sections 3 or 6 or 9 means answer = 3/11
*May 3, 2016*

**Math**

LOL, I will never say.
*May 3, 2016*

**Math**

21^2 = 441 22^2 = 484 23^2 = 529
*May 3, 2016*

**Physics**

well, I get 1.47*10^2 Joules Yes, work done = change in kintic energy
*May 3, 2016*

**Physics**

work = force * distance in direction of force 150 J = 10 d d = 15.0 m
*May 3, 2016*

**Maths yr 6**

(4/5) hr/manhouse * 3 man = 12/5 hr/house = 2 2/5 hr = 2.4 hr
*May 3, 2016*

**statistics**

50 shipped first one ok 29/50 second one 28/49 third one 27/48 etc down to eight of them then multiply
*May 3, 2016*

**history**

In question 5 I do not think the act was about age requirements but it was about racial discrimination. It allowed people of all races to register to vote and vote, and that includes primary elections.
*May 2, 2016*

**check for typos**

length or height? How many feet is A ?
*May 1, 2016*

**Math**

I already went through trying to draw a 60, 60, 60, 90 triangle with this student.
*May 1, 2016*

**Math**

You are welcome :)
*May 1, 2016*

**Math**

whew, finally someone got one right !!! :)
*May 1, 2016*

**MATH**

NO, To make D you need three 60 degree angles and a 90 degree angle. Try to draw that.
*May 1, 2016*

**MATH**

An equilateral triangle has three 60 degree angles. That leaves no corner for a 90 degree angle.
*May 1, 2016*

**baloney**

Please check for typos !! If you used length, width and thickness you probably mean ft^3 not ft^2. That messed you up big time when you wrote 144 which is square inches per square foot. What you want is CUBIC feet per CUBIC yard which is 3^3 = 27 ft^3/yd^3 ( despite the fact ...
*May 1, 2016*

**mathematics-change of subject of the formula**

(A/pi)^2 = r^2 (h^2-r^2) =-r^4+h^2r^2 r^4 - h^2 r^2 + (A/pi)^2 = 0 r^2 = [h^2 +/-sqrt(h^4-4A^2/pi^2)]/2 r = sqrt { [h^2 +/-sqrt(h^4-4A^2/pi^2)]/2 }
*May 1, 2016*

**Math**

(x-11)^2 = r^2 = x^2 - 22 x + 121 so I do not get d
*May 1, 2016*

**math**

.75 miles/4.5 min *60 min/hr = 10 mi/h
*May 1, 2016*

**typo**

If it grows exponentially you mean 15,000 * 1.07^x in other words compounding not 1.07 x In that case C is correct 1.07^12 = 2.25 A rough estimate to remember is that 7 percent compounded for ten years is about a doubling.
*May 1, 2016*

**CONVERSIONS**

there are 9 ft^2/ yd^2 because 3*3 is 9
*May 1, 2016*

**MEASUREMENTS**

0.254296875 mi^2 if it is really 162.75 acres If however that is a typo and you mean 1642.75 acres then 2.566796875 mi^2
*May 1, 2016*

**Math - typo ?**

4y = 3 x y = .75 x + 0 slope = +.75 line is not in quadrant 2 but in one or three
*May 1, 2016*

**math**

You could just as easily lose 5 or more as win five or more. The triangle is symmetric about that middle point note C = 252 for point C10,5 then 210 to the left and 210 to the right. The middle point can go either way Too bad you had an even number of questions :) That is what...
*May 1, 2016*

**Ms Sue, not symmetric. Could get 5 wrong !**

Note my check comment
*May 1, 2016*

**math**

note that if I split the probability of getting 5 right in half I would get .123 less which would be .5 :) (good check)
*May 1, 2016*

**math**

binomial distrution p(5) = C(10,5).5^5 .5^(10-5) = 252*.5^10 = .246 p(6 ) = C(10,6).5^6 .5^4 = 210 * .5^10 = .205 p(7) = 120 * .5^10 = .117 p(8) = 45 * .5^10 = .044 p(9) = 10 * .5^10 = .01 p(10) = 1 * .5^10 = .001 now add .623
*May 1, 2016*

**math trick question**

The same as the supplement of a supplement :)
*May 1, 2016*

**math**

a/b = b/(a-b) b^2 = a^2 - ab a^2 - ab -b^2 = 0 a = [b +/- sqrt(b^2 +4 b^2) ]/2 a = b [ 1 + sqrt 5 ]/2 a = 1.618 b sure enough now 3.7 could be a or b if b = 3.7 then a = 5.99 about 6 if a= 3.7 then b = 2.29 about 2.3
*May 1, 2016*

**math-middle school**

well, I suppose in some world B could be a negative angle, but not in ours.
*May 1, 2016*

**7 th grade math**

14/20 = 7/10 = 0.70 0.70 * 300 = 210 0.70 * 100 = 70 0.70 * 240 = 168
*May 1, 2016*

**Calculus**

k = P V^1.4 k = 40 * 14^1.4 k = 1609 so P = 1609 V^-1.4 dP/dt = 1609 (-1.4)(V^-2.4) dV/dt = -2253 (14)^-2.4 * -1 = 4 psi/s
*May 1, 2016*

**Math**

speed = 70+80 = 150 distance = 300 time = 300/150 = 2 h
*May 1, 2016*

**physics**

3000 * v = 15 * 1.5
*May 1, 2016*

**Math NEED HELP!!!!!!**

http://www.mathsisfun.com/geometry/construct-linebisect.html
*May 1, 2016*

**Math**

4*8 = 32 1*2 = 2 32/2 = 16
*May 1, 2016*

**physics**

185 * 8 = 1480 Joules 1480 Joules = 3537 cal
*April 30, 2016*

**Chemistry**

How many molecules do you have? Well how much mass in a mol? 3*12 + 7*1 + 16 + 1 = 60 grams for 6.022*10^23 molecules so we have 6.022*10^23 * 85.9/60 = 8.62*10^23 molecules each of those molecules has 3 carbon atoms 3*8.62*10^23 = 25.9 *10^23 =2.59 * 10^24 carbon atoms
*April 30, 2016*

**physics**

Fx = -a x^4 I assume you mean F= -25 x^4 dW = F dx = -25 x^4 dx W = -(25/5)x^5 at x = 1.25-at.75 W = -5 (1.25^5 - .75^5)
*April 30, 2016*

**Maths**

try reading here: http://www.mathsisfun.com/algebra/factoring.html
*April 30, 2016*

**math**

Yes, to do it on the number line start at 0 go left 8 to - 8 go right 14 to +6
*April 30, 2016*

**check list of answers below**

This has been asked over and over and over again, look below.
*April 30, 2016*

**typo**

You mean V = (4/3) pi r^3 dV/dt = (4 pi r^2) dr/dt (You really do not need calculus. It is the surface area times dr/dt)
*April 30, 2016*

**MATH**

No, because 3+5 = +8 , not 15
*April 30, 2016*

**math**

-9 + 5 + x = -1 -4 + x = -1 x = +3
*April 30, 2016*

**MATH**

-4 - 2 = -6
*April 30, 2016*

**Geography -Yr10**

During the second half of the 19th century, river shipping was of great importance, but, with growing competition from railways and demand for irrigation water (first used at Mildura in 1886), navigation practically ceased. ================================ In other words they ...
*April 30, 2016*

**Math**

weight at top = 15 -.1*50 = 10 average weight = (15+10)/2 = 12.5 12.5 * 50 = 625 ft pounds
*April 30, 2016*

**Math**

You are welcome.
*April 30, 2016*

**Math**

No, same answers both ways.
*April 30, 2016*

**Math**

I used the kinematics because I did not know if you knew how to integrate velocity to get distance.
*April 30, 2016*

**Math**

oh well v(t)= 38-2t or dx/dt = 38 - 2 t then x = c + 38 t - (1/2)(2)t^2 c = x when t = 0 call it 0 here x = 38 t - t^2
*April 30, 2016*

**Math**

I do not know if you know calculus or if you have kinetatic equations in your text. What we have here is a constant acceleration of -2 ft/s^2 a. 0 = 38 - 2 t 2 t = 38 t = 19 s b. d = Vi t + (1/2) a t^2 = 38 (19) - 19^2 = 19(19) = 361 feet or use average speed for 19 seconds...
*April 30, 2016*