Friday

December 2, 2016
Total # Posts: 28,227

**CALCULUS**

when x = 0, y = 1 that is y axis intercept since x^2 is always + the graph slopes down from 1 to 0 at infinity and it is always in the first quadrant. just sketch it and you will see that the rest is silly.

*April 17, 2016*

**LIFE ORIENTATION**

Where? In some places you can get together with others and protest or go to court. In others you would be thrown in jail or shot for that.

*April 17, 2016*

**Physics**

speed of light is about 3*10^8 meters/seconds so distance = 3*10^8 * (2.6/2) meters

*April 17, 2016*

**Physics**

You are welcome.

*April 17, 2016*

**Physics**

area of big face = .1*.2 = .02 m^2 so min pressure = 10*9.81/.02 Pascals and max = 10*9.81/(.1*.05)

*April 17, 2016*

**L.O**

Because most of what we know aout what is going on in politics comes from the media and if it is controlled by the government, then we only get to hear what the government wants us to hear. Of course there are other threats such as financial control of the media by a small ...

*April 17, 2016*

**Math**

8 * 10 = 80

*April 17, 2016*

**math**

sum of x values = 45 3*.14 + 6*.05 + 9*.36 + 12*.35 + 15*.1 = 9.66 9.66/45 = .215 that 6 , .05 point looks like either a typo or an outlier

*April 17, 2016*

**Hmm, I can not help**

Not having the drawing I can not do moment arms. You need the distances.

*April 17, 2016*

**mensuration**

area = 4 * 305 Which I suspect is a typo unless it is a carpet for a wedding at Taj Mahal perhaps 4 * 3.05 ??? cost = area * 42

*April 17, 2016*

**math**

I bet B starts at 80, not 8 and runs at speed v A runs at speed 2v t = 100/2v Bdistance run = v t = v(100/2v) = 50 so B is still 80 - 50 = 30 meters away

*April 16, 2016*

**Math**

sum = = m + m+1 + m+2 + m+3 but n+1 = m+3 so m = n-2 sum = 4 m + 6 = 4(n-2)+3 =4 n -8+3 = 4 n - 5

*April 16, 2016*

**Math**

10 Look at a table of binomial coefficients

*April 16, 2016*

**algebra**

300 = 5000 (.7)^n .06 = .7^n log .06 = n log .7 so n = log.06/log.7 = 7.89 years

*April 16, 2016*

**Math**

I agree, although I never thought of it that way :)

*April 16, 2016*

**American History**

Yes, A, opening up international trade helped (hear that Mr Trump?)

*April 16, 2016*

**Algebra**

cost = 2 n- 4 2n-4 > 8 2 n > 12 n > 6

*April 16, 2016*

**distribution**

http://davidmlane.com/hyperstat/z_table.html

*April 16, 2016*

**distribution**

http://davidmlane.com/hyperstat/z_table.html

*April 16, 2016*

**hey**

I am not going to just do these for you. I already took the subject (in 1958). What are your answers?

*April 16, 2016*

**pro**

p correct = .25 1-p = .75 p(0 correct)= C(10,0).25^0*.75^10 p(1 correct)= C(10,1).25^1 *.75^9 p(2 correct)= C(10,2).25^2 *.75^8 c(10,0) = 1 of course C(10,1) = 10 C(10,2) = 45 add the three probabilities C(10,1)

*April 16, 2016*

**Math**

order matters here so permutations not combinations n!/[ n-r] ! 14 !/ 9! right 14 * 13 *12 * 11 * 10

*April 16, 2016*

**physics**

Flutist hears the difference or "beat" frequency http://hyperphysics.phy-astr.gsu.edu/hbase/sound/beat.html

*April 16, 2016*

**I vote for C**

I would pick C Radiocarbon dating is usually for absolute age, but comparing samples you are likely to use ratios , perhaps even of C14 again. see: http://www.parks.ca.gov/?page_id=24000

*April 16, 2016*

**science help pls pls**

LOL, another questionable question. Are you inland somewhere? Duration is how long the waves last, not the answer Fetch is how far across the bleak ocean the wind and waves have traveled to reach you. When waves build up they start short and low, but as they travel and the ...

*April 15, 2016*

**science pls help**

Well, yes sort of as a deep water wave approaches shallow water it slows down, not really due to friction but due to the theoretical velocity of waves in deep and shallow water. In deep water V = k sqrt (wavelength) in shallow water V = K sqrt (water depth) the transition from...

*April 15, 2016*

**huh?**

area scale ratio is 1/4 so every length of a small one is 1/2 the big one's length the perimeter of the big one is 60 so the perimeter of each small one is 30 and the total is 120, not 70 SO A is FALSE B is true 10*17.3 C FALSE as shown above D false obviously 173/4 in fact

*April 15, 2016*

**Science**

You are welcome.

*April 15, 2016*

**Science**

so to get the temp in deg C from your scale multiply the number you read on the straw by (47/n) and add 20 T = (temp range/n) x + Tlow

*April 15, 2016*

**Science**

You must have made marks at two different known temperatures, Tlow and Thigh Label Tlow 0 label Thigh something then every 5 mm make a mark label them 1,2 ,3 etc until you reach Thigh let's say Thigh is at 67 degrees C and Tlow was at 20 deg C then your range was 67 - 20...

*April 15, 2016*

**chemistry**

double amount of water, same NaCl, half the concentration

*April 15, 2016*

**Equations**

Plug and Chug 3 s + 5 a = 1150 but s+a = 300 so a = 300-s 3 s + 5 (300-s) = 1150 3 s + 1500 - 5 s = 1150 2 s = 350 s = 175

*April 15, 2016*

**Math/Algebra**

S = 4 x M = 3 x B = 2 x total = 9 x = 2178 so x = 242 M = 3 x = 726

*April 15, 2016*

** no way**

a , b b - a = 29 5 a = 2 b what result is one? Makes no sense. Ignoring that. 5 a = 2 (a+29) 3 a = 87 a = 87/3

*April 15, 2016*

**L.o**

Afraid of strangers

*April 15, 2016*

**School**

No, it is not.

*April 15, 2016*

**where?**

I live in Massachusetts. We do not elect judges anywhere.

*April 15, 2016*

**math**

downstream speed = u + 4 upstream speed = u - 4 20 = (u+4) t 10 = (u-4)t so 20/(u+4) = 10/(u-4) 10 u + 40 = 20 u - 80 10 u = 120 u = 12 miles/hr

*April 15, 2016*

**English**

1. lower than usual price 2. at whatever price In 3 through 6 it is the price of the product, not the product, which is 30% off.

*April 15, 2016*

**Math--Parametric Equations**

for the center: x = 24 cos 45 * t = 17 t y = 24 sin 45 * t = 17 t relative to center initial angle of point from x axis Ai = 90 degrees (on y axis) r = 1.5 Xrel = r cos A Yrel = r sin A A = 90 + (360*3)t A = 90 + 1080 t cos A = cos (90 + 1080t) = -sin(1080 t) trig identity sin...

*April 15, 2016*

**Algebra**

3, whoa, climbing faster try y(n+1) = 3 y(n) geometric ratio is always 3 or r = 3 y = 1.4 * 3^(x) try x = 4 y = 1.4 * 3^4 = 1.4 * 81 = 113.4 it worked

*April 15, 2016*

**Algebra**

2. constant d again y = m x + b y = 2.3 x + 3

*April 15, 2016*

**Algebra**

1. note constant d = 2 arithmetic sequence straight line of slope 2

*April 15, 2016*

**Math**

right :), sorry mistook < for =

*April 15, 2016*

**Math**

ah, 4^4 * 4^4 = 4^8 like 10^1 * 10^1 = 10^2 NOT 10^1 try C)

*April 15, 2016*

**Math**

yes, yes, but numbering messed up.

*April 15, 2016*

**Physics**

You are welcome.

*April 15, 2016*

**Physics**

T = 15/25 = .6 second C = 2 pi R = 2 * 3.14 * .95 = 5.97 meter a) v = C/T = 9.94 m/s b) v^2/R = 9.94^2/.95 = 104 m/s^2 wow, 10 g c) F = m a = .025*104 = 2.6 Newtons

*April 15, 2016*

**Physics**

Just add

*April 15, 2016*

**Algebra**

good grief, g = 32 ft/s^2, old text :) T = 2 pi (L/32)^(1/2) T = 2 pi (4/32)^.5 = 2.22 seconds

*April 14, 2016*

**HISTORY HELP plsssssssss**

Well, it said it was "good" if it came from the "Maker of the world".

*April 14, 2016*

**Math**

A = L * w Perimeter = L + 2 w = 36 so L = 36-2w A = (36-2w)w -2 w^2 + 36 w = A w^2 - 18 w = -A/2 w^2 - 18 w + 81 = -A/2 + 81 (w-9)^2 = -(1/2)(A-162) vertex at w = 9 area = 162 ft^2 ==================== check if w = 9 L = 36 - 18 = 18 area = 162, sure enough

*April 14, 2016*

**Math**

x(x+5) = x^2 + 5 x

*April 14, 2016*

**Math - Please check!**

1. yes 2. yes 3. pi*3.5^2 = 38.5 yes

*April 14, 2016*

**i really need help with science pls help**

If the results are conflicting I would pick A If the results are from different branches of the same study area I would pick B

*April 14, 2016*

**Math**

Oh, Pythagoras ! http://www.mathsisfun.com/pythagoras.html

*April 14, 2016*

**Math**

well, I happen to know that 3^2 + 4^2 = 9+16 = 5^2 so 30^2 + 40^2 = 50^2 so that is a right triangle.

*April 14, 2016*

**Math**

One does not normally give heading of a breeze. You specify the direction it comes FROM. However this seems to be specifying the direction it is GOING like it were a current so I will assume that. north speed = Vn = 145 cos 84.5 + 24.6 cos 68.4 east Speed = Ve = 145 sin 84.5...

*April 14, 2016*

**Pre-Calc**

logb(4) +logb((x^7 y^2)/(z^4))^.5 logb(4) +logb((x^7 y^2)/(z^4))^.5 logb(4)+3.5 logb(x) + logb (y) - 2 logb (z)

*April 14, 2016*

**Physics**

Fx = 186 cos 22 Fz = 186 sin 22 186 cos 22 - 120 = 61 a a = (1/61) 52.5 = .86 m/s^2 v = a t = .86 t average v = .43 t 2.5 = .43 t * t t = 2.41 seconds so v = .86 (2.41) = 2.07 m/s

*April 14, 2016*

**typo**

surely something parabolic like r(t) = -30 t^2 - 390 t and that is also really nonsense on this planet where h = Vi t - 4.9 t^2 in metric units or h = Vi t - 16 t^2 in feet etc but anyway well, when t = 0 it starts we hit he ground again when 30 t^2 = 390 t or t = 13 seconds ...

*April 14, 2016*

**Physics**

m g h + (1/2) m v^2 = energy gain during trip = 610 * 9.81 * 49 + (1/2) * 610 * 24.7^2 in Joules divide that energy gain by 20.5 seconds to get Watts

*April 14, 2016*

**Math**

x(1.5) + 12(4) = (x+12) * 3 1.5 x = 12 x = 8 ============================ check 8*1.5 + 12*4 = 60 8+12 = 20 pounds total 20 * 3 = 60

*April 14, 2016*

**Stats - Help!!!**

Kasheta speed =d/22.3 Louisa speed = d/26.4 so Kasheta speed/Louisa speed = 1.18 Kasheta is 18% faster. That is meaningful.

*April 14, 2016*

**physics**

a) equal and opposite b) -charge on A, + charge on B Vb > Va so negative c) electrons the electrons move through the wire from A side to B side BUT the current is defined as if it were positive charges moving through the wire SO current through resistor from B side to A side

*April 14, 2016*

**science-college physics**

r = .001 meter Area = pi r^2 = 3.14 * 10^-6 m^2 delta L/L = F /( E A ) delta L/1 m = F /(2*10*8 *3.14*10^-6) F/delta L = spring constant = k 628 N/m now I am sure you can do the sqrt (k/m) thing

*April 14, 2016*

**physics**

FORGET k, 10^-6 etc etc which are the same for both put -9 at x = 0 put + 16 at x = 1 from negative x a + 1 charge pulled right to x= 0 but pushed left from x = +1 so left of 0, final x is negative 9/x^2 = 16/(1-x)^2 9 (x^2 - 2 x + 1 ) = 16 x^2 9 x^2 - 18 x + 9 = 16 x^2 7 x^2...

*April 14, 2016*

**Physics**

F = m v^2/r where m = 720 v = 48000/3600 = 13.33 m/s r = 200

*April 14, 2016*

**science**

P = i V = .75 * 2.4 = 1.8 Watts

*April 14, 2016*

**math**

if any dimension is multiplied by x and the shape is similar, then every length is multiplied by x including the perimeter. Google scale ratio anyway (1/2) * 54 = 27 meters

*April 14, 2016*

**PHYSICS**

to add the voltages you just add by the way, Voltage is a potential and scalar, not a vector

*April 14, 2016*

**mathematics**

sqrt (12^2 + 6^2)= sqrt 180 = 6 sqrt 5

*April 14, 2016*

**math**

I can only guess you mean 5% and 10% 1.05 x = 2142 so x = 2040 then do your 10% 1.1 (2040) = 2244

*April 14, 2016*

**algebra**

the first way is brute force finding where two lines hit The second way is called "elimination". The third way is called "substitution". They are all ways o find the intersection of those lines.

*April 14, 2016*

**algebra**

or substitute x = 1 - 3y use that in the second one -3(1-3y) -3y=15 -3 + 9 y -3 y = 15 6 y = 18 y = +3 again

*April 14, 2016*

**algebra**

there are lots of other ways, like add the two equations +1 x + 3 y = 1 -3 x - 3 y = 15 ---------------- add -2 x = 16 x = -8 then go back and get y

*April 14, 2016*

**algebra**

first equation is the line y = -(1/3) x + 1/3 second equation (-x-y=5) is the line y = - x - 5 so -x-5 = -(1/3)x + 1/3 2/3 x = -16/3 x = -8 then y = 3 ------------------- check -8+9 = ? 1 yes +24 - 9 = ? 15 yes

*April 14, 2016*

**calculus**

two similar triangles First the stationary situation x/5.5 = (x+14)/16.5 5.5(x+14) = 16.5 x 11 x = 77 x = 7 now start moving x = length of shadow y = woman to pole (x+y)/16.5 = x/5.5 16.5 x = 5.5 x + 5.5 y 11 x = 5.5 y 2 x = y so 2 dx/dt = dy /dt if dy/dt = -6 then dx/dt = -3 ...

*April 14, 2016*

**rs aggarwal math class 8 chapter 8 soluation**

n / (2n -2) (n + 3)/(2n+1) = 2/3 3(n+3) = 2 (2n+1) 3 n + 9 = 4n + 2 n = 7 so n/(2n-2) = 7/12

*April 13, 2016*

**Precalculus**

p = Pi e^kt 2 = e^10 k ln 2 = 10 k .693 = 10 k k = .0693

*April 13, 2016*

**I am not sure**

(x+y)(y+z)=5(x+y)(y+z) one cow = 5 cows Please check for typos

*April 13, 2016*

**Algebra**

>>>>>>> y - 4 --------------------- (y+3) | y^2 - y + 4 >>>>>>> y^2 +3y -------------------- >>>>>>>>>>>> -4y + 4 >>>>>>>>>>>> -4y -12 -------------------- >>...

*April 13, 2016*

**science**

m g h = 700 * 9.81 * 30 Joules Unless you find some way to store that energy and use it to move the elevator back up.

*April 13, 2016*

**geography**

Seeing as how these folks pioneered seafaring in the Indian Ocean I would consider that an important part of their economic activities : http://www.cambridge.org/us/academic/subjects/archaeology/archaeology-asia-sub-saharan-africa-and-pacific/archaeology-seafaring-ancient-...

*April 13, 2016*

**Math**

10/24 = 5/12 so this is a 5, 12, 13 right triangle 39/13 = 3 (of course 26/12 is 3 also) so 5*3 = 15

*April 13, 2016*

**statistic**

http://davidmlane.com/hyperstat/z_table.html

*April 13, 2016*

**Geometry**

120/360 = 1/3 so (1/3) pi r^2 or (1/3)(3.14)(40)(40)

*April 13, 2016*

**algebra**

.08 (25,300) .92 (25,300)

*April 13, 2016*

**math**

2058 = 14 * w * 3 w w^2 = 49 w = 7 L = 21

*April 13, 2016*

**science help pls pls**

http://lcogt.net/spacebook/parallax-and-distance-measurement/

*April 13, 2016*

**math**

1/3 +1/4 = 4/12 + 3/12 = 7/12 so 5/12 = 10 are blue blue = 24 , got it ?

*April 13, 2016*

**Math**

2 n + 5 = 5 n-16 or = 16-5n 21 = 3 n or 7 n = 11 n = 7 or n = 11/7 ====================== check if n = 7 14 + 5 = ??? 35 - 16 19 = 19 check yes if n = 11/7 22/7 + 5 = ???? 16 - 11/7 22/7+35/7 = ??? 112/7 - 55/7 57/7 = 57/7 yes, check

*April 13, 2016*

**Calculus**

h is height x is distance from wall sin T = h/13 cos T = x/13 d cos T /dt = - sin T dT/dt =(1/13)dx/dt or dT/dt = -(1/(13 sin T))(dx/dt) sin t = h/13 at x = 5 h = sqrt (169 - 25) = 12 so sin T = 12/13 so dT/dt = -(1/12)dx/dt = -1/12 radians/second

*April 13, 2016*

**Science**

P1/T1 = P2/T2 140 + 273 = T1 216 + 273 = T2 P1 = (T1/T2)22.3

*April 13, 2016*

**AP Physics**

Area L = volume so if 3 times longer, then 1/3 the area 3 * 21 = 63 ohms

*April 12, 2016*

**AP Physics**

Power = V^2/R = 5434 Watts = 5.434 kw hours = 31*9 = 279 hours so 5.434 kw * 279 hr *.15/(kw hr) = $ 227.41

*April 12, 2016*

**Maths (Proof)**

If you can squish it, it is no longer regular. The sides may be the same but not the angles. Think about a square with hinges at the corners if you squish it into a parallelogram, it still has 4 equal sides but is no longer a regular polygon.

*April 12, 2016*

**Maths (Proof)**

sqrt (2^2 + 5^2) = sqrt 29 agreed the distance from -5,5 to 5,5 is 10 the distance from 0,-7 to 7,0 is 7 Oh my :( not really regular I guess you will have to make a model with 8 equal sides and see if you can sqwish it :) I think you can.

*April 12, 2016*

**Physics**

T = k sqrt L/g sqrt(1.03/9.82) = sqrt (L/9.77) so L = 9.77 (1.03/9.82)

*April 12, 2016*

**Math**

if 40 hours is normal week length 40 x + 7(1.5 x) = 375.78

*April 12, 2016*