Sunday

April 20, 2014

April 20, 2014

Total # Posts: 16,179

**world history 2**

That is why NY caught up to those earlier big cities, the cheap shipping to and from the west through the canal.

**world history 2**

The Erie Canal connected New York City up the Hudson River and through the canal to the Great Lakes. It is much, much cheaper to ship grain and stuff by boat than by road. So that opened up the mid west and made NY a big city.

**world history 2**

http://geography.about.com/od/urbaneconomicgeography/a/eriecanal.htm

**world history 2**

LOL, now how did New York City ever catch up to Philadelphia and Boston ?

**Science**

F = m a F up from scale - m g = m a but a = -g (free fall) so F up from scale - m g = - mg so F up from scale = 0

**Science**

Well, I agree because it says changes and the cat changed direction twice, once to turn around and once to go from horizontal speed to vertical speed, thereby changing velocity without much change in speed.

**science**

To continue moving in a circle requires an inward directed force from tension in a string or banking of a curve because the object is continually accelerating toward the center. If you let it go, it would go in a straight line. The constant acceleration toward the center is ca...

**world history**

http://www.fordham.edu/halsall/islam/1876suezcanal.asp

**world history**

French built it, British used it :) Trade between the Mediterranean Sea and Indian Ocean (India to Straits of Malacca to Spice Islands, to China) dates from long before the British or French existed. However it had to include a land link from the Nile to the Red Sea or from th...

**Physical Sciences**

constant velocity means NO ACCELERATION therefore just the weight 80 * 9.81 = 785 Newtons

**science**

Inertia is the word you are looking for I think.

**college algebra**

1.07 s = 44,490 s = 44,490/1.07

**6th grade math**

each combination of small tile and large tile covers 6 inches or 1/2 foot. So it will take 12 combinations to go 6 feet That is twelve four inch tiles and twelve two inch tiles just to stretch along the wall. NOW he needs two more 2 inch tiles for each of the original ones to ...

**Chemistry 2**

Al2(SO3)3 2 Al = 54 3 S = 96 9 O = 144 -----------add 294 grams/mol so 80 grams is 80/294 = 0.272 mol of aluminum sulfite in 50 mL a liter is 1000 mL 0.272 *1000/50 = 5.44 mols/liter

**college algebra**

800 - 300 = 500 profit I am wondering what is included in that cost though. If that is what she paid the wholesaler for the computer it is reasonable because cost of her building and help and taxes etc do not seem to be included.

**English**

Momentum is product of mass and velocity. At the same speed, the heavier object will have more momentum. I think this is Physics, not English, by the way.

**History check**

I agree although I usually think of them more positively as people who started the industrial revolution in the United States.

**mathematics**

x+2 = + or - 4 x+2 = 4 x = 2 or x+2 = -4 x = -6

**S.S**

French settled mainly the St Lawrence valley and there were not many of them because the king would not let the French Huguenots come to America.

**S.S**

Heavens, look at what I wrote about why Chinese and Japanese and others from Asia came to America !

**S.S**

note: "......... several huge copper mines opened, including Highland Valley Copper—the largest open-pit operation in all of North America. ..... "

**S.S**

http://www.empr.gov.bc.ca/Mining/Pages/History.aspx I think I already answered the second question. NOT Hawaiian !

**math**

population is 6,000 batches sample is batch examined

**S.S**

In particular in California many Chinese came to help build the transcontinental railroad. Does British Columbia have any railroads ? I think I have seen pictures of the Canadian Pacific route through the Rocky Mountains. Beautiful !

**S.S**

There are native Hawaiians of Polynesian ancestry. However there are many other groups there especially on Oahu including Japanese and Chinese and Philippine groups. These people immigrated from other parts of the Pacific to work in Hawaii. Similarly many Chinese people and Ja...

**S.S**

LOL - and many Hawaiians are from ______

**Physics**

on earth I assume weight = 850 * 9.81 in Newtons

**Physics**

72 km/hr *1000/3600 = 20 m/s average speed during acceleration = (20+0)/2 = 10 m/s 104 = 10 m/s * time to stop so time = t = 10.4 seconds

**mat 116**

So what is your known value of x ? multiply it by two then subtract 20

**Polynomial**

Yes

**Math**

tan^2 = sin^2/cos^2 = s^2/c^2 (s^2/c^2+1)(c^2-1) = s^2 -s^2/c^2 +c^2 -1 but s^2 + c^2 = 1 so we have -s^2/c^2 = -(1 - c^2)/c^2 = - 1/c^2 + 1 = 1 - sec^2

**Pre-Calc**

well I suppose x^2 = t^2 -6 t + 9 for x = t-3 and for x = 3-t but t = y-3 t^2 = y^2-6y+9 so x^2 = y^2-6y+9 -6(y-3) + 9 x^2 = y^2 + 36 y^2 = x^2-36 y = (x^2-36)^.5

**Algebra**

well, 7 d m = 7 d m b^0 You have it in DESCENDING not ascending powers of b -7dm + 25d b^5 - 6d b^6 + 3 b^10

**Pre-Calc**

b^logb(x) = x so 27^log(2x-1) = 27^(4/3) = 3^4 = 9*9 = 81 so 2x-1 = 81 2 x = 82 x = 41

**Math**

cos(pi/2+x) = - sin x (draw it on a graph , angle x to the left of y axis in quadrant 2) also sin - x = - sin x so we end up with (-sin x)(-sin x) = sin^2 x

**Science**

P V = n R T constant here so 550 mL/ 22 = 25 mL

**Algebra**

I meet all the ones that left during the 6 months before I left plus all the ones that left during my trip so about 12

**Trig**

sorry typo cos x cos y + sin x sin y 5 sqrt 7/52 + 9/13 = .9467

**Trig**

cos (x-y) = cos x cos y = sin x sin y cos x = -sqrt7 /4 cos y = -5/13 sin x = 3/4 sin y = 12/13 so cos(x-y)=5sqrt7/52 - 9/13

**Physics**

zero terminal velocity means constant speed down, no acceleration so approaching terminal velocity means approaching zero acceleration

**history**

I refuse to guess because I am from New England :)

**Math**

two heads tosses are independent .55 * .55 = .3025 probability of tails = 1-.55 = .45 two tails .45 * .45 = .2025 probability of 1 head + probability of 2 heads = probability of head, then tail + probability of tail then head + probability of two heads = 1 - probability of 2 t...

**Pre-Calc**

t^2 = x+1 y = x + 1 +/- (x+1)^.5 you can manipulate that further

**Algebra**

I just used 13 because I wanted easy numbers trying x = 15 now .5 y = 12 y = 24 so 15/24 yes 15-3/24 = 1/2 yes 15/30 = 1/2 yes so 15/24 is just as good as 13/20

**Algebra**

(x-3)/y = .5 x/(y+6) = .5 ----------------- .5 y = x - 3 .5 y + 3 = x these two equations are the same, choose any old x (infinite number of solutions) if x = 13 .5 y = 10 so y = 20 x/y = 13/20 check that (13 -3)/20 = 1/2 sure enough (13)/(26) = 1/2 sure enough

**Physics**

Do you know 45 degrees gives max distance? u = 4.9 cos 45 = .707 (4.9) = 3.46 m/s 12 = 3.46 t t = 3.47 seconds in air t going up = 3.47/2 = 1.73 s upward v = Vi - g t Vi = 4.9 sin 45 = 3.46 v = 0 at top 0 = 3.46 - g (1.73) g = 2 m/s^2 max height is average speed up time time u...

**Science**

yes, you are welcome.

**Science**

mass is matter

**Physics**

u = 86 cos 32 = 72.9 m/s forever Vi = 86 sin 32 = 45.6 up at start x distance = u t 265 = (86 cos 32) t t = 3.63 seconds in the air h = Hi + Vi t - 4.9 t^2 h = 0 + 45.6(3.63) -4.9(3.63)^2 h = 101 meters high v = Vi - 9.81 t at t = 3.63 v = 10 m/s up u = 72.9 still speed = sqrt...

**English**

or mimic or imitate, too bad it is not multiple choice :)

**math**

You are welcome :)

**math**

4 x + 10 y = 14 is the first equation times 2 4 x + 10 y = 14 is the second equation there is a y for any real x, in other words an infinite number of solutions since both equations are for the same line

**Physics**

How long to drop 42 - 2.12 = 39.88 meters? h = Hi + Vi t + (1/2) a t^2 0 = 39.88 + 0 - 4.9 t^2 t^2 = 39.88/4.9 so t = 2.85 seconds how far does he walk in 2.85 seconds? d = 1.12 * 2.85 = 3.2 meters

**Physical Science**

c = (5/9)(F-32) c = (5/9)(86-32) = 30 deg C I do not know what you are using, perhaps: V = 331.4 + .6 C V = 331.4 + .6(30) = 349.4 m/s d = 349.4 * 2.3 = 804 meters period = 1/653 lambda = 349.4 * 1/653 = .535 meter

**Physics**

110 km/hr(1000/3600) = 30.6 m/s 119 km/hr = 33.1 m/s x position of truck = -211.7+ 30.6 t v car = 2.3 t until v = 33.1 at t = 14.4 s and x = (1/2)(2.3)(14.4^2) = 238 m after that xcar = 238 + 33.1 (t-14.4) so during car acceleration period: d = Xcar - Xtruck = .5(2.3)t^2 - 211...

**Physical Science**

2 d = 1400 * .16 d = 112 meters deep 2 d = v t 2 * 1000 * 3.5 = 1400 t t = 5 seconds

**Mata**

half width is 39 feet up 2/3 of 39 2 * 13 = 26 feet <----- answer by the way, roofers go by pitch = height / full width so they would call this a pitch of 26/78 = 1/3

**Science**

Google- plate tectonics mountain formation -maybe?

**MATH**

y = 55 - 11 x or the way I would say it is depth = 55 - 11 * minutes since start the y axis intercept is the value of y when x = 0 It is 55. Now what does that 55 represent?

**chemistry**

Katie, That (3/2) in moles O2 to moles KClO3 is the 2 KClO3 for 3 moles O2 in your balanced equation

**us history**

I agree with you.

**us history**

What do you think? When was the first track completed across the continent?

**algebra**

400 - 210 = 190 they have to earn 7 n >/= 190

**algebra**

5 plus three times the number of years 5 + 3x or 3x+5

**history**

Well, that is hardly a landslide :)

**history**

I would go with c myself.

**History**

The Catholic King James 2 of England was kicked out by the protestant Netherlander William of Orange in what was called the "Glorious Revolution". Protestants hated James because they thought he was trying to convert England back to the Roman Catholic Church. It was ...

**please help!**

If you mean y = -(3/8)x - 14 The graph is a straight line, try it. if you mean y = -3 /(8x) - 14 then it is certainly not a straight line.

**Physics**

m and .1 m original momentum = m VA momentum remains m Va throiughout so m Va = .1 m (Va+V) and m Va = .1 m (Va-V) + .9 m Vb so .1 m Va+.1 m V = .1 m Va-.1 m V+.9 m Vb .2 m V = .9 m Vb so V = 4.5 Vb but m Va = .1 m Va + .1 m V so V = 9 Va so 9 Va = 4.5 Vb Vb/Va = 2

**Algebra 1**

Value = 14,000 + k t k = (9000-14000)/2 = $-2500/year so V = 14,000 -2500 t when t = 5 V = 14,000 - 12,500 = 1,500

**chemistry**

That is why I used (3/2)

**chemistry**

at STP, a mol of perfect gas occupies 22.4 liters so we need to know how many moles How many grams in 1 mol of K Cl O3 ? K = 39 Cl = 35.5 O3 = 16*3 = 48 --------------- mol = 122.6 grams so 3.5 grams of KClO3 = .0286 mol for every mol of KClO3 I get 3/2 mol of O2 so (3/2) (.02...

**Math**

You are welcome :)

**Math**

Independent (number of white knights/number of white pieces) * (number of black pawns/number of black pieces)

**physics**

multiply the mass by the velocity to find the momentum

**Physics**

F = m g = G M m /R^2 so g = G M/R^2 = 6.67*10^-11*6.15*10^23/[(3.25^2)*10^12] = 3.88 * 10^0 = 3.88 m/s^2 about 1/3 of earth g weight = m g = 79.4 * 3.88 = 308 Newtons

**math(algebra)**

-3 - 1 = -4 2 - 6 = -4 sqrt [(-4)^2 + (-4)^2] = sqrt (2*16) = 4 sqrt 2

**Physics**

before x momentum = 17,000 (east) y momentum = 17,000 (north) after m Vx = 2000 V cos T = 17,000 still m Vy = 2000 V sin T = 17,000 still so sin T = cos T so T = 45 deg and sin = cos =sqrt2 /2 2000 V (sqrt 2/2) = 17,000 V = 17 /sqrt 2 = 12 m/s

**Physics**

F = change in momentum/change in time F = (0 - 18,000) / 12 F = - 1500 Newtons

**Physics**

momentum before = 2 * 3 + 4*0 = 6 momentum after = 6 kg * v so 6 v = 6 v = 1 m/s

**Physics!**

F dt = change in momentum = 46(0-3) = -138 kg m/s

**Physics**

momentum before = momentum after 1.2 * 4 = 2.4 * v

**Calculus Help**

f(x) = 1/[ x^.5 +1 ] f(z) = 1/[ z^.5 + 1 } f(x)-f(z) = 1/[ x^.5 +1 ] - 1/[ z^.5 + 1] = ([z^.5+1]-[x^.5+1])/(x^.5z^.5 +x^.5+z^.5+1) = (z^.5-x^.5) /(x^.5z^.5 +x^.5+z^.5+1) Divide by (x-z) which is (x^.5-z^.5)(x^.5+z^.5) and get -(x^.5+z^.5) / (x^.5z^.5 +x^.5+z^.5+1) let z --->...

**math**

.25 x for food .25 * .75 x for drink = .1875 x .25 x + .1875 x = .4375 x spent x - .4375 x = 9 .5625 x = 9 x = $ 16

**MATH**

http://www.jiskha.com/display.cgi?id=1393604312

**MATH**

Hey, I did this already 6 - 2 = 4 still

**Algebra 2 Help**

[4 - 7i] + [2 + 3i] just add 6 -4i

**Algebra 2 Help**

7 + 24i r = sqrt (49 + 576) = 25

**Algebra 2 Help**

8sqrt[-63] not much I can do but put an i in 8 i sqrt 63

**Algebra 2 Help**

3x2 + 2x = 12 - 7x 3 x^2 + 9 x - 12 = 0 x^2 + 3 x - 4 = 0 (x+4)(x-1) = 0 x = 1 or x = -4

**Algebra 2 Help**

1) 2x^2 -24 x + 40 = 0 x^2 - 12 x + 20 = 0 (x-2)(x-10) = 0 x = 2 or x = 10

**math**

( sqrt 6 + sqrt 2)(sqrt 6 - sqrt 2) note, to remember for any a and b (a+b)(a-b) = a^2 - b^2 so 6 - 2 is 4

**physics**

horizontal 10 sin 20 vertical 10 cos 20 you did not specify up or down or right or left so you do the signs

**physics**

Hi = 50 Vi = 30 v = Vi - 9.81 t at top v = 0 so t = 30/9.81 = 3.06 seconds to top h = Hi + Vi t - 4.9 t^2 h = 50 + 30(3.06) - 4.9(3.06)^2

**Science please help**

It is the outer (valence) electrons that participate in bonding. They do so either by giving one of their outer electrons to the other element thereby producing two atoms of opposite charge which attract each other (ionic bond) or by sharing outer electrons (covalent bond) The...

**no picture**

If you copied and pasted a figure, that does not work here.

**math**

secret is 75 = 3 * 25 = 3 * 5^2 5 sqrt ( 3 ) + 2 sqrt ( 3 * 5^2 ) 5 sqrt ( 3 ) + 10 sqrt ( 3 ) 15 sqrt ( 3 )

**math**

I do not understand your symbol but suspect it is square root sign If so then 2 sqrt (20 x) + 3 sqrt (5x) 2 sqrt (4*5 x) + 3 sqrt (5x) 4 sqrt (5 x) + 3 sqrt (5x) 7 sqrt (5 x)

**math**

x y = 3.2 so y = 3.2/x x + y = 3.6 x + 3.2/x = 3.6 x^2 - 3.6 x + 3.2 = 0 x = [ 3.6 +/- sqrt (12.96 - 12.8) ]/2 x = [ 3.6 +/- .4 ] /2 use the positive root x = 2 y = 1.6

**math**

always multiply by (1 +r/4) each period so the same ratio every year (1+r/4)^4 so both I think

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