Sunday

April 20, 2014

April 20, 2014

Total # Posts: 16,179

**Vectors**

We need to know the slope of the ramp, if friction is important, and if the object is on earth.

**Math**

You are welcome :)

**Math**

least common multiple of 6 and 8 is 24 teeth clashing that is 4 turns of the 6 and 3 turns of the 8

**physics**

The wording of this question puzzles me because if they are in orbit they feel no gravitational force since the centripetal acceleration (v^2/R) exactly balances earth gravity. However if you wish to separate out those two factors then use Forbit = G m Me / Rorbit^2 Fground = ...

**I do not understand**

do you have a typo or is that something I just do not know about?

**calc**

z = 2 cosine 60 + 2 i sin 60 z= 2 e^i(60) z^4 = 16 e^i(240) = 16 cos 240 + 16 i sin 240 = 16 (-.5 )+ 16 i(-.866 ) = -8 - 13.86 i

**physics**

in degrees or radians? 1.834 degrees or .032 radians note, for small angles sin (Theta) = Theta in radians

**Math**

yes, use x

**Math**

if i </= 20,000 tax = .15 * i if i> 20,000 tax = 3,000 + 0.20 ( i - 20,000)

**chemistry**

NaNO3 Na = 23 N = 14 O3 = 3*16 = 48 total = 85 Na = 100 * 23/85 N = 100 * 14/85 O3 = 100 * 48/85

**Physics**

I will assume the inclined block wins and slips down the hill Force up on inclined block = T force down slope on inclined block = 28 (9.81 )sin 53 - 28 (9.81)(.9)cos53 a = acceleration down slope 28 a = 28 (9.81 )sin 53 - 28 (9.81)(.9)cos53 - T Force down on hang mass = m g = ...

**physics**

wires are 60 degrees from vertical so T cos 60 = 110 T (1/2) = 110 T = 220 N

**science**

( T cos 60 = 110 T = 220 N

**algebra**

a) +(4x-3/6) = +(5-5x/10) b) -(4x-3/6) = +(5-5x/10) c) +(4x-3/6) = -(5-5x/10) d) -(4x-3/6) = -(5-5x/10) a and d are the same, scratch d b and c are the same, scratch c so a) +(4x-3/6) = +(5-5x/10) b) -(4x-3/6) = +(5-5x/10) so solve those last two :)

**Engl.**

Writeacher knows far more about this subject than I.

**Engl.**

"planned to seize" looks like a simple predicate to me. If it said: "planned to seize immediately" I would say "planned to seize" was the simple predicate and "planned to seize immediately" was the complete predicate

**Engl.**

agree

**Algebra**

You are welcome :)

**Algebra**

4/2 = 2 8/4 = 2 16/8 = 2

**integer**

1.66 is not a whole number and is not an integer. However it can be written as 166/100 and is therefore a rational number unlike for example pi = 3.14159 .......... see: http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&ved=0CDQQFjAB&url=http%3A%2F%2Fwww.t...

**EARTH SCIENCE- SO STUCK**

Well, the speed of compression and shear waves depends strongly on the characteristics of the ground they are passing through. We could get answers all over those choices depending on what we chose for the difference in speed. Your text or course notes must have given you typi...

**EARTH SCIENCE- SO STUCK**

The difference in speed is maybe 8 km/s these are 5*60 = 300 seconds apart so 8 * 300 = 2400 km

**Physical science**

F = d/dt (mv) in other words force is rate of change of momentum (in the special case of constant mass this is F = m a) so F * change in time = change of momentum This is usually called "impulse".

**Science**

mass has nothing to do with this unless air resistance is a factor v = -g t h = H + Vi t - .5 g t^2 0 = 33.5 + 0 - 4.9 t^2 4.9 t^2 = 33.5 t = 2.61 seconds to fall v = - 9.81 * 2.61 = -25.9 m/s

**ASAP Help thankies everybody History**

The US was hardly in a position to weaken the British economy. British trade was world wide at the time and just their trade in the West Indies, or East Indies for that matter, overwhelmed any trade they had with the USA. They liked getting wood for ships and masts and tar and...

**Physics Help**

39,000 m/3600 s = 10.83 m/s average speed during braking = 10.83/2 = 5.42 25 = 5.42 t t = 25/5.42 = 4.62 seconds to stop v = Vi + a t 0 = 10.83 + a (4.62) a = -2.34 m/s^2 1/4 g is not an unreasonable deacceleration

**Physics**

vertical speed observed = -37.9 sin 50.8 = -29.4 m/s how far did it fall to reach -29.4 m/s? v = -g t -29.4 = -9.81 t t = 2.99 s d = 4.9 t^2 = 4.9 (2.99)^2 = 43.9 so it reached 43.9 + 22.5 = 66.42 m vertical speed at ground? fell from 66.42 m 66.42 = 4.9 t^2 t = 3.68 s v = -g ...

**Algebra**

.6 x = x - 50 50 = .4 x x = 125 take it from there

**physics**

i = V/R = 60/25 = 2.4 amps P = i v = 2.4*60 = 144 watts or Joules/second Joules into water = 144 t where t is in seconds 144 t = C (.5)(100-29) I do not recall C, specific heat of water in Joules/ kilogram deg centigrade

**Calculus HELP!!**

Except that indeed 8 - 6 - 2 = 0 I have no idea what you mean. Are x1 and x2 vectors multiplied by square matrices or what?

**Algebra**

yes A yes c

**Quick math help**

You do not need us to check. Put your answers back in the original equations. as for #10 -56x+72y=-16 -49x+63y=-14 divide top by 2 divide second by 7 -7 x + 9 y = -2 -7 x + 9 y = -2 NO solution. This is the same line repeated, no intersection In linear algebra if one row is id...

**physics (clear answer)**

vertical problem first Vi = 16 sin 38.5 = 9.96 m/s v = Vi - g t = 9.96 - 9.81 t h = Hi + Vi t - (1/2) g t^2 3 = 0 + 9.96 t - 4.9 t^2 4.9 t^2 - 9.96 t + 3 = 0 t = [ 9.96 +/- sqrt(99.2-58.8) ]/9.81 t = [9.96 +/- 6.36 ] /9.81 t = 1.66 seconds in air v = 9.96 - 9.81(1.66) = -6.36 ...

**Finance - Annuities**

first 4 years S = 4000 [ 1.08^4 -1 ]/.08 = 18024.45 second 4 years first what happens to the 18024.45 that we have in the account. It earns 11% compounded yearly 18024.45 (1.11)^4 = 27362.38 In addition we have 1500 per year deposited S = 1500 [1.11^4 -1 ]/.11 = 7064.60 27362....

**Physical Science**

(1/2) m v^2 = 25 * 100 = 2500 Joules

**Algebra**

that is b^2 ------------ 2 a^4 4^2 -------- 2 (-2)^4 16 ------- 2(16) 1/2

**Algebra**

81 * 10*-6 = 8.1 * 10^-5 I have no idea. use parentheses or write it like this 1 ----------- 2 a^-4b^2 or do you mean this? (1/2) a^-4 b^2 or maybe 1 ------------- b^2 2 a^-4

**algebra**

y+16=3y that is all you need ! 2 y = 16 y = 8 3 y = 24 the end

**MATH CHECK ANSWERS**

Scroll down. I did these.

**math**

80 t - 60 t = 420 assuming both going north, which avoids customs at the border 20 t = 420 t = 21 hours

**MATH CHECK ANSWERS**

1. There are 18 boys and 12 girls in a math class.what is the ratio of girls to total students? A.18:30 B.12:30(I PICK THIS) <----Yes C.30:12 D.30:18 2.which of the following ratios are equivalent to 6:9? Choose all that apply. A.3:2 B.18/27 C.30:45 <<------ I pick t...

**Algebra**

m q^2 / n^4 that is A I pick

**Math**

x y x - y = 4 well, five and one will do 51

**Math**

x = amount per topping b = base price for cheese 15.25 = b + 3 x 17.75 = b + 5 x ----------------subtract -2.5 = -2x x = 1.25 Not 1.15 I think 17.75 = b + 5 (1.25) b = 11.50

**Algebra**

1/(5*9) = 1/45

**Algebra 1**

y = 0.6 x x>0

**Please help with Physics Quickly**

Impulse is integral F dt , change in momentum Impulse is average force times time of interaction Impulse = F t -------------------------- The way I think about it: I do not really use F = m a I think F = d/dt(mv) the rate of changer of momentum (By the way, that works even whe...

**URGENT Physics PLEASE help**

1600 * 24 south 150 * 8 m = p/v = 200/.8

**Algebra (Word Problem)**

y = x - 50 domain x>100 domain is the part of the x axis where the function is valid for example the function y = 1/x domain is 0< x <0 but does not include x = 0 where it is undefined

**physics**

F * d = energy lost to friction = (1/2) m v^2 m g mu d = (1/2) m v^2 9.81 mu (8) = .5 (16) = 8 mu = 1/g = about .1

**physics**

E = k Q/r^2 direction away from Q since Q is positive

**Calculus**

area = (1/2) a b b = 10 - a area = (1/2) a (10 -a) = (1/2) 10 a - a^2 If we were doing algebra we could find the vertex of this parabola but since you said calculus, we will use calculus dArea/da = 0 when max or min dArea/da = (1/2)(10 - 2 a) 2 a = 10 a = 5 b = 5

**physics**

same old formula E = k Qe/r^2 N/C Qe = - 1.6*10^-19 Coulombs r = 3 * 10^-3 meters k = 9 * 10^9 N m^2/C^2 E is toward negative charge

**physics**

Now wait a minute, your questions are really all the same question. The only difference is arithmetic. F = k Q1Q2 /r^2

**Physic**

a = F/m F = q E so a = q E/m 13 = q (5)/0.108

**Physic**

m g = k q^2/r^2 1.67 * 10^-27 * 9.81 = 9*10^9 (1.6*10^-19)/r^2

**Physic**

1/r^2 gets big when r gets samll

**Physic**

they are the same magnitude and opposite in direction like any other forces

**maths**

2(x+4) + 1/5 2 x + 8 + 1/5

**Algebra**

4^4 * 10^12 256 * 10^12

**Calculus**

2 0 -1 2 6 5 3 7 2 -1 0 4 -------------------------- 1 0 -1/2 1 0 5 6 1 0 -1 1 2 ------------------------------ 1 0 -1/2 1 0 1 6/5 1/5 0 0 11/5 11/5 ---------------------- 1 0 -1/2 1 0 1 6/5 1/5 0 0 1 1 so z = 1 now work back up get x = 3/2 y = -1 z = 1

**in parallel or series?**

I do not know

**math**

10.0 - 7 x = .90 7 x = 9.1 x = 1.3 meters

**Fractions**

You are welcome :)

**Fractions**

then when you take a yellow out, you have 2 blue and one yellow remaining

**Fractions**

Two of the four birds in the store were yellow.

**Fractions**

well, first I have to do it b - 1 = total birds at end yellow birds: (1/2) b - 1 = (1/3)(b-1) b/2 = 1 -1/3 + b/3 3b/6 -2b/6 =2/3 b/6 = 2/3 b = 4 yellow = b/2 = 2 put 4 balls in a box, half of the yellow, and do the experiment

**Pre Calcu**

{ 4 +/- sqrt (16 + 88) ] /4 [ 4 +/- sqrt(104) ]/ 4 [ 4 +/- 2 sqrt (26) ]/4 1 +/- 0.5 sqrt(26)

**physics**

(A+B)x = -3.82 (A+B)y = 8.24 14.6 + 67.9 = 82.5 so 9.08

**Physic II**

F = k q^2/r^2 so q = r sqrt (F/k) r = .008 F = 4 k = 9 * 10^9

**Science - 6th grade**

The snake seems to be in charge of controlling the lizard populations, a function fulfilled by a keystone species.

**American History**

If you mean Charlestown (Bunker Hill), no way

**American History**

I think you mean Cowpens which was Greene but only indirectly Cornwallis although he was in overall command of that British army.

**statistics**

Is that a question?

**Math**

Need I go on?

**Math**

25 q + p = 232 q + p = 25

**American History**

We had a fine smuggling business here and one customs person representing the crown lived right down the street from where I live now, until the pole and the tar and feathers.

**American History**

In that article: Effects on American colonies " ... The Navigation Acts, while enriching Britain, caused resentment in the colonies and contributed to the American Revolution. The Navigation Acts required all of a colony's imports to be either bought from England or r...

**American History**

Yeah, I know. I just don't agree :) ( I am from Cape Ann)

**American History**

I might have been inclined to join my friends around New England in B

**Calculus**

int dx/x^2 = -1/x + c from 1 to 3 = -1/3 - (-1/1) = 2/3 half of that is 1/3 from 1 to a = -1/a - (-1/1) = -1/a + 1 so -1/a + 3/3 = 1/3 -1/a = -2/3 2 a = 3 a = 3/2

**English**

Not that one.

**English**

Well, we disagree on every single one of them. Look these words up in a dictionary! 1. When it came time for the reading of their fathers will, the family was surprised. They knew their father was PARSIMONIOUS, yet they expected that he would BEQUEATH more to them than he did....

**physics**

we want our east component to equal our north component so we get 45 degrees resultant. Wind is FROM 270, west. Heading or compass direction is clockwise from North wind is going 90 or East so our East speed is 320 sin(heading) + 32 and our north component is 320 cos (heading)...

**History8**

http://learn.genetics.utah.edu/content/gsl/physical_char/

**History8**

hot and dry -----> water evaporates

**math**

In that case it depends on a lot of things, mainly: The temperature of the ice. Skates move easily over the ice because they melt a tiny film of slippery water under the blade. If the ice is very cold, the skate will have to be very, very sharp to work efficiently. On the othe...

**math**

I have no idea. It depends on friction. Where did you get this question?

**geometry**

In general h = 2*area/base here the base is EG = 21 the area is sqrt[ s(s-a)(s-b)(s-c) ] where s = (a+b+c)/2

**geometry**

10, 17, 21 IS NOT a Right triangle, no hypotenuse here

**Math help**

-280 = -35 * 8 -280 =-56 * 5 sorry, 280 not 200, does not matter, solution is origin (0,0) anyway both of those lines are through the origin having no b in y = m x + b

**Math help**

in the second one both 56 and 49 have common factor 7 which we will take advantage of 56 = 7 * 8 49 = 7*7 so use 7*7*8 = 392 56 *7 = 392 so multiply first by 7 49 *8 = 392 so multiply second times 8 I think you can take it from there.

**Math help**

we must find a common multiple of something here 15 = 3*5 24 = 3*8 so I guess we could use 3*5*8 = 120 15 * 8 = 120 so multiply first eqn by 8 24 * 5 = 120 so multiply second by 5 - 280 x - 120 y = 0 - 200 x + 120 y = 0 -------------------- add -480 x = 0 so x = 0 and y = 0 wh...

**History**

I am in the middle of reading a book: Lincoln Paine, "The Sea and Civilization" or I would be of little use here.

**History**

1 agree B 2 agree B 3 agree B

**History**

Yes, skipping over the golden stool.

**History**

I am puzzled by this one because all your other questions were about Africa. However the Kushans were not from Kush in Africa but their empire was around what is now more or less Afganistan in Asia. They did indeed evidently move there after disagreements with their Xiongnu ne...

**History**

The Bantu eventually took over South Africa, driving the San into the desert. I am not sure how long it took. I am not aware of them building cities. That does not seem their thing at all.

**History**

Swahili incorporates a lot of Arab words as well as words from languages that arrived even later.

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