Wednesday

October 7, 2015
Total # Posts: 22,103

**math**

along diameter 28/4 + 1 = 8 around semicircle pi D/2 = 14 pi = 14(22/7) = 44 meters or 11 spaces none at ends, already there, so 11-1 = 10 total of 18
*January 9, 2015*

**History**

... and it was Turkey, Greece and Iran in the Middle East by the way. ... and what about Eastern Europe - Poland, Hungary, etc
*January 9, 2015*

**math**

p pencil p - 15 = rulers 3(p-15) = books total = p + p - 15 + 3 p - 45 = 5 p - 60
*January 9, 2015*

**math**

yes 12+3 = 15 :)
*January 9, 2015*

**U.S History**

Google history of US presidential cabinet
*January 9, 2015*

**Science - Please answer as soon as possible**

I would pick b.
*January 9, 2015*

**physics**

weight down = mass times centripetal A down mass cancels, does not matter g = v^2/R
*January 9, 2015*

**incomplete**

You need to know the magnitude of the pulling force. If mass and coef of friction are given and the velocity is constant then it is horizontal force = F cos 30 = m g (mu-sin 30) W = F cos 30 * 20*10^3 J
*January 9, 2015*

**LA - 1 question**

1.
*January 9, 2015*

**Geometry**

A is your statement of the problem B subtract two from both sides C multiply both sides by 6
*January 9, 2015*

**Social Studies help**

If you look at the products on that tree, it looks like we all use coal in one way or another :)
*January 9, 2015*

**Social Studies help**

http://www.coaleducation.org/lessons/twe/bytree.htm
*January 9, 2015*

**Math**

29500 + .041*128500
*January 9, 2015*

**Math**

Yes cos = 0 sin = 1
*January 9, 2015*

**physics**

882 *3.8/9.8
*January 9, 2015*

**Physics and Math**

ball rolls distance 1 + x loss of height = (1+x)sin 30 = .5(1+x) loss of potential energy = 1*9.8*.5(1+x) gain of potential energy = .5 k x^2 = .5 x^2 so 9.8(1+x) = x^2 x^2 - 9.8 x - 9.8 = 0 x = [ 9.8 +/-sqrt(96+39.2)]/2 x = (9.8+/-11.6)/2 x = 10.7
*January 8, 2015*

**Incomplete**

So what is the question ?
*January 8, 2015*

**MNHS_HELP**

I drew 6 8*8 5*5 3*3 2*2 two 1*1
*January 8, 2015*

**English**

I suppose you could say the social context was very lonely, just the nut case and the poor old man. In other words isolated.
*January 7, 2015*

**Physics**

m g sin theta 4 * 9.81 * (1/2) about 19.6 N
*January 7, 2015*

**Science**

Yes, in fact it was Thorium.
*January 7, 2015*

**Science**

it depends on what medium to what medium. Fastest in a vacuum
*January 7, 2015*

**Math**

yes, with some left over.
*January 7, 2015*

**math**

1260 miles (6 gallons/180 miles) = ?
*January 7, 2015*

**Math**

there are more 81 s than anything else
*January 7, 2015*

**Math**

I assume you mean: -x^2/4 + 9 x/5 + 2 = y complete the square first multiply by -4 x^2 - 36 x/5 - 8 = y x^2 - 36 x/5 = y+8 x^2 - 36 x/5 + (18/5)^2 = y + 8 + 12.96 (x-18/5)^2 = y + 20.96 so vertex at ( 3.6 , -20.96)
*January 7, 2015*

**adding and subtracting rational**

(11*8)/(15*8) + (1*15)/(8*15) = 88/120 + 15/120 = 103/120
*January 7, 2015*

**Physics**

infinitely fast, constant acceleration forever m a = m * 9.81 * sin 10.3 so a = g sin 10.3 = 9.81 sin 10.3 so v = (9.81 sin 10.3) t v is proportional to time, forever
*January 7, 2015*

**physics**

(T-30)(10 kg) (heat capacity of water) = 5000
*January 7, 2015*

**physics**

m v^2/r = m g so m cancels of course, has to be the same no matter how many in the car :) v= sqrt (r g)
*January 7, 2015*

**Physical Science HELP**

Zn + I2 ---> ZnI2 the end
*January 7, 2015*

**Math**

I assume x/(x^2-3x-4) - 4/(x+1) ????? x/[(x+1)(x-4)] - 4(x-4)/[(x+1)(x-4)] -3x+4 /[(x+1)(x-4)] blows up if x = -1 or x = 4
*January 7, 2015*

**algebra 2**

(x+4)(x-1) = 0 y = x^2 + 3 x - 4
*January 7, 2015*

**math**

.4 * 50 = 20
*January 7, 2015*

**Math**

x = x^2 + xy + x + y 0 = x^2 + y (x+1) y = -x^2/(x+1)
*January 7, 2015*

**math**

1 1/4 = 5/4 bags 7 1/2 = 15/2 pounds /bag so (5/4) bags *(15/2) pounds/bag = 75/8 = 9 3/8 pounds
*January 7, 2015*

**math**

365.75 km ( 1 hr/133 km) = 2 3/4 hr = 2 hours and 45 minutes
*January 7, 2015*

**Chemistry**

F2O3 ??? 2Fe2O3 + 3C --> 4Fe + 3CO2 ??? maybe mols of Fe2O3 = 3.79*10*24 /6.02*10^23 = 6.30 mols Fe2O3 or 12.6 mols Fe Fe is 56 g/mol so 12.6 * 56 = 706 grams Fe `
*January 7, 2015*

**Math**

sin 24 = h/30 h = 30 sin 24 = 12.2 ft note - do not climb ladder that barely reaches the eaves.
*January 7, 2015*

**Physic**

c = q/v same q on each, call it q so c1 V1 = c2 V2 so V2 = (c1/c2) V1 and V1 + V2 = 1000 V1 + (c1/c2)V1 = 1000 but c1/c2 = 3/6 = .5 so 1.5 V1 = 1000 V1 = 667 V2 = 333 I think you can go back and get q = v c for each
*January 7, 2015*

**Maths**

a + d (n-1) a + d = 7 a + 4 d = 22 ------------ -3 d = -15 d = 5 so a = 2 2 , 7 , 12 , 17 , 22
*January 7, 2015*

**math**

6 / (1/3) = 6 * 3
*January 7, 2015*

**physics**

force = change in momentum/time = (50 kg * 5000 m/s) /s = 250,000 Newtons thrust weight = m g = 60,000*9.81 = 588,600 N no way
*January 7, 2015*

**physics**

m = 30/9.81 a) (30/9.81)v = .005 * 300 b) (730/9.81)v = .005 * 300
*January 7, 2015*

**math**

4.5 in ( 20 mi/in) = 90 miles 90 miles (1 in/18 mi) = 5 inches
*January 6, 2015*

**physics**

(1/2) m v^2 start = m g h at top so m g h = 2 * 10^4 m = 2*10^4 / (9.81*50) = 40.8 kg
*January 6, 2015*

**Science**

Probably with carbon 14 dating. http://dwb4.unl.edu/Chem/CHEM869Z/CHEM869ZLinks/www.all.mq.edu.au/online/edu/egypt/carbdate.htm
*January 6, 2015*

**physics**

5.72*10^3 * 3.11 * 10^3 = 17.8 * 10^6 = 1.78 * 10^7 Joules
*January 6, 2015*

**Math**

30/20 = 1.5 , 90/60 = 1/5 the same 15/20 = 3/4 , 10/15 = 2/3 NOT the same
*January 6, 2015*

**Math**

I would say A
*January 6, 2015*

**Science**

You are welcome
*January 6, 2015*

**Math**

a + d(n-1) a + d (2) = 1985 a + d(7) = 2015 ----------------subtract 0 - 5 d = - 30 d = 6 a + 12 = 1985 a = 1973 1973 + 6(14) = 2057
*January 6, 2015*

**physics**

normal force down = 18.4*9.8 - 126 sin 34.1 so friction force = .123 (18.4*9.8-126 sin 34.1) work done by friction - friction force * 20 meters
*January 6, 2015*

**Science**

Yes That is all per molecule.
*January 6, 2015*

**4th grd math**

3*8 = 24 fish per day 2.5 * 8 = 16 + 4 = 20 eaten so 4 left over each day I guess you do not have seagulls where you live :)
*January 6, 2015*

**Math**

15 sandwiches /.75 hr * 3 hr = 60 sandwiches
*January 6, 2015*

**Science**

You are welcome.
*January 6, 2015*

**Science**

I mean (6/18)*10^23 atoms/gram
*January 6, 2015*

**Science**

2 hydrogens, one oxygen in a molecule so three atoms per molecule a mol is 6*10^23 molecules so 18 * 10^23 atoms per molecule a mol weighs 2+16 = 18 grams so (6/18) * 10^23 molecules per gram
*January 6, 2015*

**math**

sorry, yes
*January 6, 2015*

**math**

39 - 15 = 25 spaces so 25,000 feet 10:11- 10:05 = 6 minutes 25,000/6 = 4167 feet/min a little less than a mile a minute or 60 miles per hour
*January 6, 2015*

**math**

1/4 inch to the foot so one inch = 4 feet 6*4 = 24 feet
*January 6, 2015*

**math**

14/10 = 1.4 lions per tiger or 14/24 = 7/12 lions (not loins I assume) and 10/24 = 5/12 tigers
*January 6, 2015*

**algebra**

there will be a short time on the way up to 28 and a long one for the way down, we want the second minus the first when will h = 28 feet? 28 = 4 + 56 t -16 t^2 16 t^2 - 56 t + 24 = 0 2 t^2 - 7 t + 3 = 0 (2t-1)(t-3) = 0 t = .5 or t = 3 so t = 2.5 seconds above 28
*January 6, 2015*

**Math**

dollars / t shirts = dollars per t shirt A 40/16 = 2.50 per shirt B 140/84 = 1.67 per shirt
*January 6, 2015*

**Math**

You are welcome.
*January 6, 2015*

**Math**

7 d - 4 d - 32 = -8 3 d = 24 d = 8
*January 6, 2015*

**math**

oh, I assumed that the 23 was a typo and it meant 2/3
*January 6, 2015*

**math**

I think you added 6 girls and get 20 out of 30
*January 6, 2015*

**math**

Rodger is right
*January 6, 2015*

**math**

3/7 7+10+7 = 24 total students 14 are girls so 14/24 = 7/12 suspect you mean 2/3 are girls (14+x) /(24+x) = 2/3 42 + 3 x = 48 + 2x x = 6 more girls
*January 6, 2015*

**Math**

" it is also perpendicular line" should be it is at the intersection of two perpendicular lines.
*January 6, 2015*

**math**

I guess. There are lots of ways to do it actually.
*January 6, 2015*

**math**

6 * 5^2 = 6 * 25 = 600/4 = 150 12* 5^3 = 12 * 125 = 1500 1500 * 150 = 225,000
*January 6, 2015*

**math**

The one with a right angle.
*January 6, 2015*

**Physics**

(1/2) m v^2 = m g h so v = sqrt (2 g h) = sqrt (2*9.81*4)
*January 6, 2015*

**Math**

4 * 4.5 = 18 pineapple 8 * 4.5 = 36 orange 12 * 4.5 = 54 seltzer
*January 6, 2015*

**Math**

I mean multiply each number of cups by 4.5
*January 6, 2015*

**Math**

4+8+12 = 24 cups 108/24 = 4.5 so multiply each number of cups by 6 to get 108 cups Note, a serving is evidently not a cup because 24 cups is 18 servings. I do not know if this is an intentional confusion or a typo.
*January 6, 2015*

**Math**

I agree with you.
*January 6, 2015*

**civics**

Protect all citizens in time of trouble***
*January 6, 2015*

**civics**

I agree with you. The last.
*January 6, 2015*

**civics**

I agree, although I am tempted by the first choice :)
*January 6, 2015*

**Physics**

http://www.jiskha.com/display.cgi?id=1420573371#1420573371.1420574332
*January 6, 2015*

**Physics again?**

Just did that
*January 6, 2015*

**Physics**

I will have to assume that it goes the entire 100 meters during this deceleration and crashes into the moon at .5 m/s -.5 = -20 + a t 100 = -20 t + .5 a t^2 a = (-.5+20)/t -100 = -20 t + .5 (20-.5) t 100 = 20 t -9.75 t t = 9.75 seconds to slow down (part b) a = +2 up (part a...
*January 6, 2015*

**Civics**

You are welcome.
*January 6, 2015*

**Civics**

To ensure the powers of each branch of government are limited and checked by another branch
*January 6, 2015*

**Math**

600 - 280 = 320 100 (320/600) = 53.33
*January 6, 2015*

**Math**

time = distance/speed 5/(x/5) + 30/(5x) + 20/x = 25/x + 6/x + 20/x = 51/x she has gone 5 + 30 + 20 = 55 km b) 2 = x/5 so x = 10 and time = 51/10 = 5.1 hr c) 40 = 5x x = 8 time = 51/8 = 6.375 difference = 6.375 - 5.1 = 1.275
*January 6, 2015*

**Bosaso**

http://davidmlane.com/hyperstat/z_table.html
*January 6, 2015*

**Physics**

u = 53/2 = 26.5 m/s forever v = Vi - 9.81 t h = Vi t - 4.9 t^2 = 54 =Vi(2)-4.9(4) or 54 = 2 Vi - 19.6 so Vi = 36.8 m/s ========================== at top, v = 0 0 = 36.8 - 9.81 t t = 3.75 seconds at top but we know u = 26.5 m/s so D = u t = 26.5 * 3.75
*January 6, 2015*

**mechanics and heat**

2 v^2 = 100 v = 10/sqrt 2 = speed of 2 kg mass 4 (10/sqrt 2) = .4 V V = 100/sqrt 2 speed of small mass (1/2)(.4)(10,000/2) = 1,000 = Ke of little mass
*January 6, 2015*

**Physics**

70*5 - 5*20 = 75 v
*January 5, 2015*

**Physics**

increase of length = L *coefficient of expansion * 30
*January 5, 2015*

**Algebra**

1.35 s + 1.85 t = 1.65 * 20 s + t = 20 so s = (20-t) =========================== 1.35 (20-t) + 1.85 t = 33 solve for t, go back and get s
*January 4, 2015*

**math/compound**

40 periods at a rate of .0615/4 2500 (1.015375)^40=2500(1.841) = $4602.55
*January 3, 2015*

**physics**

since you did not specify the direction very well (41 deg from horizontal or vertical? up or down from horizontal? Up or down from vertical?) I will have to be very general in the answer. Vi = 9.66 sin or cos or -sin or -cos of 41 v = Vi - g t at top v = 0 0 = Vi -9.81 t so t...
*January 3, 2015*

**Algebra2**

g = -32 ft/s^2 in the feet (old American - English) system so (1/2)g = -16 Watch out, most of us use metric units g = -9.81 m/s^2 in which case h = Hi + Vi t - 4.9 t^2
*January 3, 2015*