Thursday

April 24, 2014

April 24, 2014

Total # Posts: 16,220

**calculus**

3 * 2 pi = 6 pi radians/minute pi/6 = 30 degrees by the way I call your angle theta A dA/dt = 6 pi rad/min tan A = x/7 x = 7 tan A dx/ dt = 7 d/dt(tan A ) = (7/cos^2A) dA/dt cos^2 (30) = .75 so dx/dt = (7 miles/.75)(6 pi rad/min) dx/dt = 176 miles/min * 60 = 1055 miles/hr so d...

**Algebra**

Oh, yes, I did not notice your answer, which is correct.

**Algebra**

This is a pretty fundamental question. What do you think the answer is?

**Math Time**

You better get an analog clock so you can run your finger over the face. I knew we were all in trouble when the digital time started. 1:30 to 2:30 is an hour, 60 minutes this is 15 minutes LESS !!!

**calculus**

by the way, d/dt (tan A) = sec^2 A * dA/dt = (1/cos A)^2 * dA/dt

**calculus**

Hey, I just did one very much like this. Your turn.

**Math Time**

1:30 - 2:30 = 60 min 2:30 - 2:50 = 20 min 60 + 20 = 80

**Calculus**

y = 1 e^(rx) y' = r e^(rx) y" = r^2 e^(rx) r^2 - 4 r + 1 = 0 r = [4 +/- sqrt (16 -4) ] /2 r = [ 4 +/- 2 sqrt 3 ]2 r = 2 +/- sqrt 3

**flagpole math**

How far away is he? Otherwise I can only give you the function. man is p from pole (we need this) shadow tip is s from pole we want ds/dt s/5 = (s-p)/1.5 1.5 s = 5 s - 5 p 3.5 s = 5 p s = 1.43 p ds/dt = 1.43 dp/dt but dp/dt = 1.8 so ds/dt = 2.57 m/s

**Algebra word problem**

yard 48 x^2 + 36 x + 6 patio 3 x^2 + 16 x + 5 subtract 45 x^2 + 20 x + 1

**calculus**

Oh, it is pointed at the bottom? area = pi r^2 radius = (1/3) h for 1 at the top and 0 at the bottom so surface area A = pi (1/9)h^2 for h = 2.6, A = 2.36 meters^2 d V = A dh dV/dt = A dh/dt or dh/dt = (1/A)dV/dt dV/dt given as 1.4 m^3/min so dh/dt = 1.4/2.36 = .593 m/min

**MATH**

Does the problem ask for the vertex? the zeros? what?

**what about it ?**

That is a parabola, do you want to graph it or what?

**math**

2 x^2 + 2 = 2 (x^2+1) so what? There is no problem here, you do not say what you want.

**Physics**

Floor pushes up total weight = (39.7 + 65.3)(9.81) crate pushes up on person = (65.3)(9.81)

**Algebra**

well the way I see it it is (6 x^3 - 18 x ) + (5 x^2 - 15) which is 6 x ( x^2 - 3) + 5 (x^2 - 3) get it ?

**AMERICAN HISTORY**

Dutch in New York, Germans in Pennsylvania, Swedish in Delaware, Catholics in Maryland, which would you pick.

**math 2**

How many cereal boxes does he want to put in the big box?

**english**

I think it is more likely the birds and bees than elves though.

**english**

1. agree 2. I have a hunch it is d 3. yeah, ok 4. I think a

**physics**

weight = m g friction force = mu m g so static mus 75 = mus (20)(9.81) and kinetic muk 60 = muk (20)(9.81)

**Physics**

well, If he jumped up, all bets are off. If he just fell off then: v = sqrt (2 g h) because m g h = (1/2) m v^2 conservation of energy g h = (1/2) v^2 so v = sqrt (2*9.81*15) = 17.2 meters/second

**Algebra**

6x*2x - 6x*3 - 5*2x + -5*-3 12 x^2 - 18x - 10 x + 15 12 x^2 - 28 x + 15

**math**

that is 39 ------------- 2 x + 1 - 10 x which is 39 ---------------- 1 - 8x

**math**

so it is 39 ------------------------ (2x+1) -2x(5) ?

**math**

I do not understand it what is the numerator and what is the denominator?

**math**

18 is divisible by 3 6 9 18 and 2 1 row of 18 6 rows of 3 9 rows of 2 2 rows of 9 etc

**English**

2 - I think d I agree with the others

**Science**

Not unless the panel charged a battery in it.

**Algebra**

77 x^2 = lot area 6 x^2 = house footprint area 77x^2 - 6 x^2 = 71 x^2

**SCIENCE**

1. yes 2. All scientists use meters to measure distance to help eliminate confusion. ---------------------------------- 3. yes 5. yes 6. yes 7. yes 8. yes

**physics**

speed at bottom = sqrt(2 g h) = sqrt (2 * 9.81 * .38) = 2.73 m/s momentum before crash = .6*2.73 = 1.64 kg m/s same momentum after of course new mass = .6 + .94 = 1.54 kg so 1.64 = 1.54 v v = 1.06 m/s

**English**

A seat might not be a chair but places on a couch or bench or two car seats for children left in the corner to be picked up by grandmother when she comes to take them to the concert I suppose. Listen carefully in hearing could be listen carefully in the budget hearing before t...

**opposition of imperialism speech**

Something more like that maybe? I did not do it very well but perhaps you can start there.

**opposition of imperialism speech**

I oppose imperialism for many reasons. Imperialism shouldn't be the cause of many resources being stolen, a weaker nation enslaving the people of smaller nations, or using them as cheap labor, so they live in poverty while you gather the benefits of their cheap labor. The ...

**opposition of imperialism speech**

http://www.merriam-webster.com/dictionary/imperialism To me imperialism means a strong country beating up on weaker ones and colonialism is am implication of imperialism. Examples would be Imperial Rome or the British empire. This paragraph seems more to address despotism rath...

**math**

21 + 19 + 17 ... a (a+d) (a + 2d) ..... a+7d eight terms where a = 21 and d = -2 arithmetic series sum of first 8 = (8/2) (42 + 7(-2) ) = 4 (42 - 14) = 4 (28) = 112

**mathematics**

BEEN THERE , DONE THAT http://www.jiskha.com/display.cgi?id=1394116813

**Algebra 1**

44 lbs * (1 kg /2.2 lb) = 20 kg 20 kg * (5 mg/kg) = 100 mg

**pre cal**

zero

**physics**

normal force = m g cos 45 so friction down slope = .3 m g cos 45 at 45 sin 45 = cos 45 = sqrt 2/2 weight down slope = m g sin 45 15 N = m g sin 45 + .3 m g cos 45 15 N = (m g sqrt 2/2)( 1 + .3) 30/1.3 sqrt 2 = m g = weight if friction he other way then F up = (m g sqrt 2/2)( 1...

**math**

Tn = a + a+d + a+2d .... + a +(n-1) d T3 = a +2d T8 = a + 7 d so a + 2d = 2 (a+7d) a + 2d = 2 a + 14 d a + 12 d = 0 a = -12 d sum of first 25 = (n/2)[ 2a +(n-1)d ] = (25/2) [ -24 d + (24) d ] LOL !!! = 0

**Math- NOT CALCULUS**

Hey, I told you use completing the square to find the vertex, boring. 2 n^2 - 84 n = - p - 45 n^2 - 42 n = -p/2 - 22.5 n^2 - 42 n + (21)^2 = -p/2 -22.5 + 441 (n-21)^2 = - (p/2 - 418.5) (n-21)^2 = - (1/2) (p - 837) so 21 taxis making 837

**algebra**

-9 x + 10 y = -9 10 y = 9 x - 9 y = (9/10) x - 9/10 slope = 9/10 well, the y axis intercept is y when x = 0 10 y = -9 y = -9/10

**finance**

That is beyond my pay grade Carol. You need a financial software package. Google "yield to maturity" The semiannually confuses the issue but I am not sure it matters much and perhaps you can use the 6% You have to assume you reinvest the interest. You have to figure ...

**Physics**

distance engineer moved = 500 m = .5 km average speed = (84.2 +16.4)/2 = 50.3 km/hr (during constant acceleration you can use the average of first and last for the distance and time) time = distance/speed = .5km / 50.3 km/hr = .00994 hours * 3600 = 35.8 seconds

**Chemistry**

p v = n R T n and R the same so P1 V1/T1 = P2 V2/T2 T1 = 18 + 273 T2 = 273 P1 = 980 Torr P2 = 760 Torr V1 = .35 V2 = ?

**Physics**

charge has no effect on mass

**VARIATION- ALGEBRA 2**

Hey Amy, you should be able to do these now.

**VARIATION- ALGEBRA 2**

x = k v^2 30 = k (625) k = 30/625 x = (30/625)(1600) = 76.8 ft

**Algebra 2- Translations**

LOL - I have no idea what is going on with this function

**Physics**

m g down mu m g friction force F = m a mu m g = m a a = mu g = .4 (9.81) = 3.92 m/s^2 a = change in speed/time change in speed = v average speed during stop = v/2 distance = average speed * time 5 meters = v/2 t so t = 10/v a = v /(10/v) = v^2/10 so v^2/10 = 3.92 v^2 = 39.2 v ...

**math**

3 / 7

**Math**

P(20) = -2(400) + 84(20) - 45 if you do not know calculus, find vertex of parabola by completing square. I am assuming calculus. 0 = -4 n + 84 n = 21 at maximum so Pmax = -2(21^2) + 84(21) - 45 21, been there, did that -45 when n = 0

**Algebra 2- Variation**

I guess you mean y = k x^2 sqrt z 49 = k (4)(5) k = 49/20 y = (49/20)(1)(4) = 49/5

**Math**

what your teacher did was say g =-10 m/s^2 F = m g = m a so a = -10 m^s^2 then v = Vi - g t = Vi - 10 t h = Hi + Vi t - (10/2)t^2 Vi = 20 v = 0 at top = 20 - 10 t so t at top = 2 h at top = 60 + 40 - 20 = 80

**wrong, typo **

but I think I see the problem you mean H = -5 t^2 + 20 t + 60 when t = 0, the height is 60. That is the height of the cliff if t = 2 h = -5(4) + 20(2) + 60 = -20 +40 + 60 = 80 when dH/dt = 0 or vertical speed is 0 it stops going up 0 = -10 t + 20 t = 2 seconds to top (that is ...

**Algebra 2- Variation**

You are welcome :)

**Algebra 2- Variation**

w = k r/p^2 25 = k (5)/16 k = 5*16 = 80 so w = 80 r/p^2 16 = 80 r/64 r = 16*64/80 = 12.8

**Pre - calculus**

(cos/sin)/(1/ cos^2)+(cos/sin)/(1/sin^2) cos^3/sin + cos sin cos^3/sin + cos sin^2/sin cos (cos^2 + sin^2)/sin but cos^2 + sin^2 = 1 so cos/sin or cot x

**Physics**

so in my head I am supposed to have stored the Young's modulus of steel ? delta L/L = tensile stress/E or delta L = F L /(E A) F = 4700 N A = (pi/4) .005^2 meters^2 L = 1.2 meters E = you look it up

**Math**

1. no, x = 15

**math**

12 + 10 = f/2 22 = f/2 f = 44

**Physics**

F = G M m/r^2 = m Ac so Ac = G M/r^2 G = 6.67 * 10^-11 M = 6 * 10^24 kg Copy this 4175 miles = meters into a Google search box and get r = 6.72*10^6 meters and 90 minutes is 5,400 seconds

**math**

combinations of n people r at a time = n!/[ r! (n-r)! ] n = ? r = 2 36 = n!/[ 2 (n-2)! ] 72 = n! /(n-2)! 72 = n (n-1) the rest cancels 72 = n^2 -n n^2 - n - 72 = 0 (n-9)(n+8) = 0 n = 9

**Physics**

There is no horizontal force. Therefore the horizontal velocity REMAINS CONSTANT v = - g t = -9.81*5 = 49 m/s down

**Math**

h = 37 t - t^2 at t = 10 h = 370 - 100 = 270 dh/dt = 0 at top = 37 - 2t t = 37/2 = 18.5 seconds to top h = 37(18.5) -18.5^2 = 342 when is h = 0 again? t(t-37) = 0 t = 37 seconds (which of course is 18.5 times two)

**Math**

do you mean (sinT - 1/cosT) or do you mean (sinT-1)/cosT

**physics**

F = G M m /d^2 6.67*10^-11*7.8*10^23*2.5*10^4/57.8*10^16 =2.25 * 10^0 = 2.25 N

**Physics**

for a more elaborate analysis see http://www.braeunig.us/space/propuls.htm read starting around equation (1.11)

**Physics**

initial momentum = 4.6*10^4 * 6.3*10^3 = 29 * 10^7 kgm/s no external forces so that is the final momentum final momentum = ship mass m *7.84*10^3 + exhaust momentum exhaust mass = (4.6*10^4 - m) what is the exhaust speed? I assume that 4.86 * 10^3 is relative to the space ship...

**physics**

(1/2) m u^2 = m g (Hup - Hdown) so u = sqrt(2*9.81*.954) u is horizontal speed, does not change How long in the air? Well, how long to fall .256 m ? .256 = 4.9 t^2 solve for t, time in the air distance horizontal = d = u t

**Physics**

work in = potential energy stored = (1/2) k x^2 double x, four times the energy stored so four times the work in.

**Math!**

You do not need help which ones start with 9 for example? you have a 97, 99, 92, 91, 94, 95, 93, 97 so 9| 1 2 3 4 5 7 7 9

**Physics**

initial momentum = 3.7 * 5 = 18.5 kg m/s mass after crash = 3.7 + 2.0 = 5.7 kg so 18.5 = 5.7 u u = 3.25 m/s which is the horizontal speed until it hits the floor. NOW I DO NOT BELIEVE that your table is 6.9 meters high so I will just outline the rest How long to fall h meters?...

**math**

slope = (7/3) y = (7/3) x + b -3 = (7/3)(-3) + b -3 = -7 + b b = 4 so y = (7/3) x + 4 or 3 y = 7 x + 12

**Math**

initial price = p marked up is 1.1 p then marked down is .9(1.1) p = .99 p

**SCIENCE**

Your stomach

**Intermediate Algebra**

p = 2 L + 2 w 192 = 2 L + 2 w L = 2 w so 192 = 2 (2w) + 2 w 192 = 6 w w = 32 etc

**math**

360/10 = 36 degrees for each piece 3 * 36 = 108 degrees total for the three slices

**Math.**

the first one I am sure is a. Scroll down and look at where this was posted a few minutes ago.

**phy**

how long to fall 50 meters? d = 4.9 t^2 t = sqrt(50/4.9) = 3.19 seconds so how far did it go horizontally? d = u t = 10 * 3.19 = 31.9 meters

**Science**

probably, depends how long it is sitting there and how cold it was when it came out of the freezer and what its specific heat and heat of fusion is and what its shape is, a long tube will melt faster than a sphere of the same mass as you know.

**Science**

NOT a !!!!! c = 3 * 10^8 m/s like period NOT b !!!! either can have any old amplitude for c and d , go look at that chart in the link I gave you earlier

**ALGEBRA! URGENT.**

3 | 7 8 9 ---> 37, 38 , 39 4 | 1 3 7 ---> 41 , 43 , 47 5 | 2 4 ---> 52 , 54 and a. is: a. 37, 38, 39, 41, 43, 47, 52, 54 so I do not think c is right. I am not educated enough in this to look at the rest.

**Physics**

3/4 = .75 hour at 70 ---> 52.5 1/6 = .167 hr at 95 ---> 15.8 1/2 = .5 hr at 55 ---> 27.5 20/60 = .333 hr at 0 --> 0 total time = 1.75 hours total distance = 95.8 km so 95.8 km / 1.75 hr = 54.7 km/hour

**typo**

w = -13 is the other choice, no good

**Intermediate Algebra**

w(w+5) = 104 w^2 + 5 w - 104 = 0 w = [ -5 +/- sqrt (25 + 416)] /2 w = [ -5 +/- 21 ]/ 2 w = 8 or w = 13 L = 8+5 = 13 then A = 8*13 = 104 w = 13 is too big so 8 by 13

**Algebra**

24 x^3 - 3 3 (8x^3 - 1) now 8 x^3 = (2x)^3 perfect cube and 1 = (1)^3 perfect cube and a^3 – b^3 = (a – b)(a^2 + ab + b^2) note a^3-b^3 not +

**Typo**

speed downstream = 12 + c

**Algebra**

Tom can row at the rate of 12 kilometers per hour in still water. He rows upstream for two hours and returns in one hour and twelve minutes. Find the rate of the current. D=r*t R=12 km per hour T= two hours --------------------------- speed upstream = 12 - c speed downstream ...

**Algebra**

Dukes chain saw requires a ration of oil to gas 1 to 40. How many ounces of oil should he add to one half gallon of gas? 8 oz = 1 cup 2 cups = 16 oz = 1 pint 2 pints = 32 oz = 1 quart 4 quarts = 128 oz = 1 gallon By the way " a pint is a pound the world around" :) so...

**Algebra**

A Piece of rope that is 63 meters long is cut into three pieces such that the second piece is twice as long as the first and the third piece is three meters longer than the second. Find the length of each piece. 2x+3x+x=63 --------------------------- need to be more orderly fi...

**Algebra**

Erin has three more dimes than nickles and twice as many quarters as dimes. she has a total of $5.05 How many of each type of coin does Erin have 5.05= 2q-d-3d-n -------------------- but they have different values nickels = n, value = .05 n dimes = (n+3), value = .10(n+3) quar...

**social studies**

inte så mycket Rus

**social studies**

I suspect Scandinavia. Sweden settled Delaware first but I wonder why the Dutch in New York are left out. http://www.colonialswedes.org/History/History.html

**Algebra**

You are welcome :)

**Algebra**

1.08 x = 1620

**Algebra**

same deal with the mowers 1/6 + 1/2 = 1/t 2/3 = 1/t t = 1.5

**Algebra**

Joe does 1/6 room/hour Theresa does 1/10 room per hour together they do (1/6+1/10) = 5/30 + 3/30 = 8/30 = 4/15 of a room /hour so 15/4 hours/room (about 4 hours)

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