# Posts by Damon

Total # Posts: 31,613

**math**

p/c = 14/12 so p =14c/12 = =7c/6 p - c/2 = 56 ====================== 7c/6 - 3 c/6 = 56 4 c/6 = 56 c/6 = 14 c = 84 (and 42 were sold) p = 7 c/6 = 98 cows = 5 c/4 = 105 84+98+105 check my arithmetic !

**Math/Physics**

I assume actually that v is POSITIVE(gliding forward) Normal force = m g = 85*9.8 = 833 N Friction force back = .09*833 = 75 N Wind force back = 2 N total force back = 77 N acceleration back (probably you call negative) = -77/85

**Math**

Ax = 4, Ay = 0 Bx = 1, By = 3 so A+B = 5i+3j Ex = -1, Ey = -3 Fx = -2, Fy + -3 so E-F = 1i+0j Bx = 1, By = 3 Cx =-2, Cy = 0 B+C=-1i+3j so -(B+C) = 1i -3j B and E 1i-3j + -1i+3j

**Geometry**

3 , 4 , 5 right triangle with 3 down from center, 5 hypotenuse radius ball center to surface intersection with table, 4 radius of cut 3 + 5 = 8

**Science**

the density of water is greater than most wood. The alcohol density is less than most wood force up = volume of fluid displaced *density * g. if water, the volume displaced can be less than the volume of the wood. If alcohol, the total volume of wood totally submerged does not...

**Math**

11 17 23 29 35 41 47 53 59 An = 11 +(n-1)6 A9 = 11 + 8*6 A9 = 11 + 48 A9 = 59

**whoops**

I mean (-1/4)

**Algebra**

An+1 = An * r is An+1 = An * (-4)

**Math**

well, first try 1.06 * what = what the next year? so after 2 years 1.06 * 1.06 * original so after n years 1.06^n * original does it increase in half a year?

**Math**

at x = 12 2x+1 = 25 7x-4 = 80

**statistic**

p(too much) = 3/4 = 0.75 1-p = 0.25 n = 7 , c = 0, 1 , 2, 3 C(7,0) = 1 C(7,1)=7 C(7,2)=21 C(7,3)=35 p(0) = 1*.75^0*.25^7 = .25^7=.00006 P(1) = 7*.75^1*.25^6 = .00128 P(2) = 21*.75^2*.25^5= .01153 P(3) = 35*.75^3*.25^4= .05768 add them :)

**Physics**

went total of 6-4 = 2 blocks east (x axis) went 2 blocks north (y axis) net is sqrt (2^2+2^2) = 2 sqrt 2 northeast which is 45 degrees north of east

**Maths**

The perimeter of a rectangle is twice the length plus twice the width

**Math**

draw number line what does it look like when both are + ?

**Maths**

34500 + 5600 sketch this problem on a number line

**Projectile motion**

There is an easy way. Doing vertical problem only: Vi = 45 sin 50 as before Now the vertical problem can be done for object thrown straight up and the horizontal component added in later. Conservation of energy: (1/2)m Vi^2 = (1/2) m v^2 + m g h where h is the height above ...

**Projectile motion**

u = horizontal speed = 45 cos 50 forever vertical problem: v = 45 sin 50 - g t h = 45 sin 50 t - .5 g t^2 at ground h = 0 .5 g t^2 -45 sin 50 t = 0 t (.5 g t -45 sin 50 ) = 0 t = 0 of course, the start and t = 45 sin 50 /.5 g so at crash v = 45 sin 50 - g(45 sin 50/.5g) v = 45...

**Projectile motion**

It is a parabola with the vertex at the midpoint peak height. If the landing is at the same level as the takeoff the thing will hit at the same speed as it took off.

**Math**

plug and chug h = 10 - x v = pi x^2 h + (2/3) pi x^3 = pi x^2(10-x) + (2/3) pi x^3 = pi [ 10 x^2-x^3 + (2/3)x^3 ] = (pi/3) [30 x^2 - x^3 ] = (pi x^2/3)(30 -x)

**hey, you can do this**

Well, what do you think?

**Statistics**

You have to know how much the average teaching asst makes

**History**

I would buy the gold and slaves molasses and sugar :) LOL, I live near Boston. That was a whole other continent and thing with the molasses and sugar and rum :) You cross the Sahara to get from Egypt to Kenya?

**History**

The do not choose this one choices for malia are often pretty entertaining. Someone out there is having fun.

**Algebra 1**

No solid includes the end open circle does not include the end point https://www.google.com/search?q=inequality+symbols+on+number+line&ie=utf-8&oe=utf-8

**History**

You are welcome.

**History**

I agree. The crown made Virginia a Royal Colony after the public corporation failed.

**sat math**

t = training hours m = meeting hours t + m </= 16 m = 2 t t >/= 2 so m>/=4 so t+m >=6 t must be at least 2 t + 2 t </= 16 3 t <=16 t </ 16/3 = 5 1/3 2 </ t </= 5 1/3 so I get 5 1/3 - 2 = 3 1/3

**Math**

30/12 = 2 6/12 = 2 1/2 meters

**Algebra**

go 1/5 mile and have 4.50 left to spend 1/5 = .2 (1/5) mile = 38 cents 1 mile = 190 cents so $1.90/mile after first .2 miles 4.50 = 1.90 * x x = 2.67 miles after .20 miles so 2.87 miles

**precalc**

cos (pi-x) is x degrees above the -x axis in quadrant II Draw it and look at the triangle cos(pi-x) = - cos x sin(pi-x) = + sin x or I suppose use trig cos(A-B) = cosA cos B + sin A sin B so cos(pi-x) = cos pi cos x + sin pi sin x = -1 cos x + 0 sin x

**Physics, need help now**

average speed during stop = 7.5 m/s t = 3 meters/7.5 m/s = .4 second v = 15 + a t 0 = 15 + .4 a a = -37.5 m/s^2 F = ma = 90(-37.5) = -3375 Newtons ouch !

**calculus**

at 2 pm say ship a is at the origin and sailing east at 10 kn at 2 pm ship b is at (0, -5) and sailing south at 5 kn say time t is time after 2 pm xa = 10 t yb = -5 - 5 t if s is separation distance s = sqrt(xa^2 + yb^2) s^2 = xa^2 + yb^2 2 s ds/dt = 2 xa dxa/dt + 2 yb dyb/dt ...

**Science**

Are there cells in a piece of steel?

**Physics 1**

22 cos 5.7

**math**

well, 9*8 is 72 so try 0.85 for example

**History**

Kind of like my way or the highway. If you live in my colony you buy your machines from me and you sell your lumber and sugar to me, like period. Try: https://www.google.com/search?q=mercantilism+in+the+colonies&ie=utf-8&oe=utf-8

**Math**

3 * 8.99 + 2*1.50 + 1.25

**Math**

a bit more than half of 380 is a little more than 190

**math HELP PLEASE**

7*25 = 8*25-25 = 200-25 = 175 cm 175 cm = 1.75 meter $4.41 / 1.75 = dollars/meter

**math**

2/3 + 1/4 + x = 1 8/12 + 3/12 + x = 1 11/12 + x = 1 looks like x is 1/12

**History**

You are welcome.

**History**

1. and 2. and 3. Yes, Pope, Treaty of Tordesillas 4. Hey, most of South and Central America speaks SPANISH. In Brazil they speak Portugese so YES FALSE

**By the way**

https://en.wikipedia.org/wiki/Strait_of_Malacca

**History**

You are welcome :)

**History**

Oh yes, I was so busy laughing at the others that I forgot to say that I agree about C

**History**

The Japanese did what ???? The papacy did what ??? Now what were all those Portuguese and Dutchmen doing around the Straits of Malacca? Now this move by the Chinese is raeally, really imaginative!

**math**

13300 - 3000 = 10300 so 800 + 0.07*10300

**AP Chemistry**

HCl = 1 + 35.5 = 36.5 grams/mol so we need 22 grams /36.5 = .603 mol of HCl .603 mol * 1000 mL/5.2 mol = 116 mL

**Science**

I agree.

**Physics**

v = a t = 2*10 d = (1/2) a t^2 = 10^2

**SCIENCE**

acid

**Maths**

If you walk around the n sides each of length 4.05 cm you travel 486 cm so n = 486/4.05 = 120 looks almost like a circle

**physics**

delta P = m (V2-V1) F = d/dt(mV) = m (V2-V1)/t

**physics**

Power = work/time = Force * speed so force = power/speed = k v^3/v = k v^2 what else is new?

**physics**

phase 1: av speed = 4/2 = 2 m/s x = 0 + 2 t = 4 meters phase 2 v = 4 m/s x = 4 + 10*4 = 4 + 40 phase 3 Vi = 4 m/s Xi = 44 average v = 2 x = 44 + 2*4 = 52 meters total work done by resistance during phase 1 = 500 N * 4 meters =2000 Joules kinetic energy gained during phase 1 =(...

**enough alreaady**

Hey, I already know how. You try this time.

**Physics**

(1/2) m v^2 = m g H so v = sqrt(2 g H) the second time Vg = speed at ground final Ke = initial Ke + amount gained in fall (1/2) m Vg^2 = (1/2)mv^2 + mgh (1/2) m Vg^2 = (1/2)mv^2 + (1/2)mv^2 Vg^2 = 2 v^2 Vg = v sqrt 2

**History**

Your book says this in no uncertain terms I am sure but anyway: http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/impact-european-diseases-native-americans

**Math**

LOL oh well :)

**Math**

LOL, Calculus really f(x+h) = 7(x+h)^2 -x-h + 3 = 7 x^2 + 14 xh + 7 h^2 -x -h + 3 now subtract f(x) = 14 xh +7h^2 -h now divide by h = 14x + 7 h - 1 That is the end of the problem. To do the derivative you now look at it when h = 0 df(x)dx = 14 x - 1

**Math**

65 + .5 x = .7 x .2 x = 65 x = 65/.2

**Chemistry**

what is the volume of 20 g of water? 20 g /1.071 g/mL = 18.674 mL so 197 *10^-3 g KCl /18.674*10^-3 L = 10.55 grams/liter Mol mass of KCl = 74.5 grams/mol (10.55 grams/Liter)/74.5 grams/mol = .142 mols/Liter

**Math**

5. 2 5/6 X 1 7/8 A. 2 35/48 B. 5 5/16 C. 5 35/48 D. 6 4/16 ======================= look, these are really all the same 2 5/6 = (12+5)/6 = 17/6 1 7/8 = (8+7)/8 = 15/8 so product = (17*15)/(6*8) = (17*5)/(2*8) =85/16 = 5 5/16 Another way is using distributive property (2 + 5/6...

**Math typo **

area is proportional to length dimension squared for similar objects D^2/d^2 = A/a Howevr what you typed makes no sense. 1. diameter of basketball is not in square inches If the diameter is 9.5 inches, the area is not 1810 area = 4 pi r^2 =4*3.14*4.75^2 =283 in^2 by the way ...

**Chinese**

This might help: https://www.mdbg.net/chinese/dictionary?page=worddict&wdqb=zhe&wdrst=0

**Algebra**

2(1+pi^3) ? about 64

**Algebra 2**

when is it zero (cross x axis?) z (z^2 +7 z +10) = 0 z (z+2)(z+5) =0 so at z = 0 , z = -2 , z=-5 if z<-5 try z = -6 -6(-4)(-1) is -24 so NO then between -5 and -2 try -3 -3(-1)(2) = +6 so YES between -1 and 0 try -.5 -.5(1.5)(4.5) = - so NO bigger than 0, try +1 1(3)(6) = ...

**Math**

Hmmm Writeteacher practicing presidential tweets :)

**Physics**

m g = 5*10 = 50 Newtons (on earth)

**Physics**

moved down 1.8 not 5.3 meters

**History**

mean, they were wicked mean.

**Math**

F = k x 15 = k *10 k = 1.5 check: 24 = 1.5 x x = 16 sureenough so 1.5 oz/inch = 1/1.5 inches/oz = 2/3 = 0.6666.... in/oz

**Math**

o + y = 21 o = 7 + 6 y so 7 + 7y = 21 y = 2

**Math**

.075*original = 0.39 so original = 5.2 (must be an old text book) new = 5.2*1.075 = 5.2+.39 I hope :)

**Algebra 1**

24 = 1.20 x

**Physics**

100 cm = 1 meter g = -9.81 m/s^2 (1/2) m v^2 = m g h v = sqrt (2 g h) v = sqrt (2*9.81*1)

**Physics**

t1 = 5/11.3 = .4425 hour t2 = 5/14.9 = .3356 hour waiting time = difference= .1069 hr = 6.415 minutes = 6 minutes and 25 seeconds

**science**

agree (but Googled :) https://www.google.com/search?q=size+of+milky+way+galaxy+in+light+years&ie=utf-8&oe=utf-8

**Physics**

phase 1 a = 58.8 and t = 5 Hi = (1/2) a t^2 = 29.4*25 = 735 meters Vi = a t = 58.8 * 5 = 294 m/s Phase 2 a = -9.81 m/s^2 v = Vi - a t v = 294 - 9.81 t v = 0 at top t = 30 seconds more h = 735 + 294(30) -4.9 (30^2) = 735 + 8811 - 4410 = 5136 meters

**math**

sum of distances from point on ellipse to foci = 2a where a is long semisaxis = 3 so 2 a = 6 = string length b = 2 (short semiaxis) center to focus =sqrt(3^2-2^2) = sqrt(5) = 2.236067977 feet which is tough with a ruler :)

**math**

4 a y = x^2 4 a (8) = (36/2)^2 32 a = 18^2 a = 10.125 in vertex to focus = a = 10.125 inches

**whoops**

Sorry about that, it said net !

**Chemistry**

well KBr is likely to be aqueous and ionized, if it is not then you have KBr solid and not the ions on the right. H+ + Br- + K+ + OH- --> K+ + Br- + H2O

**Physics**

Ah, so there is a question :) a = 3.6/.11 m/s^2 d = (1/2) a t^2 or to make it really easy average speed = 3.6/2 = 1.8 m/s distance = 1.8 m/s * .11 s

**Physics**

a = (3.6 -0)/.11

**math**

slope = 1/5 y intercept = 1 y = (1/5) x + 1 or 5y = x + 5

**physics**

F = - .69 m g = m a so a = -.69 g v=Vi + a t v = 18.0 - .69 g t v = 18 - .69(9.81)(1.29)

**Chemistry**

You are welcome :)

**Chemistry**

same number of mols of NaCL so half as many per liter 0.250 M

**Physics**

(a) no acceleration so +280 N (b)max friction force = 62*9.8*0.70 so -425 N

**Algebra2**

yikes c. if D = r t then t = D/r (you KNOW that :) 30 yards/6.47 yards/sec = 4.64 sec You KNOW it would not take him 194 seconds !!!! d. Julio runs at 9.11/2 = 4.555 yards/second 40 yards/ 4.555 yards/sec =8.78 seconds Which you already know is TWICE as long because half the ...

**math**

1 - ( [1-cos^2]/[1+cos] ) = ? cos 1 - (1-cos)(1+cos)/(1+cos) = ? cos 1 - (1-cos) = ? cos yes cos = cos :)

**Physics**

g = 9.81 = v^2/R at bottom m(9.81 + 4v^2/R) using v from part A

**science - Yes correct**

Yes, correct

**PreCalculus**

The right hand side says sin x You must make the left hand side come out sin x That is what I did Yes, I also used sin^2 + cos^2 = 1 in saying 1 - cos^2 = sin^2

**Math help**

first divide I get x^2 + 7 x +(7+k) with R = 3+k second divide I get x^2 + 4 x + (k-8) with R = -2k+12 so k+3 = -2k+12 3 k = 9 k = 3

**Calculus 1**

at some time between 2:00 and 2:10 if it is continuous and differentiable the acceleration must hit the average acceleration. (25 -20) mph/(10/60 hour) or in more usual units (36.67 - 29.33) ft/sec/600 seconds

**science**

x = 2 t + (1/2)(2) t^2 and x = (1/2)(6) t^2 so 3 t^2 = 2 t + t^2 2 t^2 -2 t = 0 t (2 t - 2) = 0 t = 1 x = 3

**math**

yes one could say though if you are into arithmetic and geometric sequences 80 + 70/100 + 70/10,000 .... 80 + .70 + .70/100 +.70/100^2 + .70/100^3 .. = 80 + .70(1/.99) geometric sequence sum

**Algerba 2**

yes, when t = 0, h = -20+20 = 0 if you are graphing (t,h) yes when t = 0, h = 0 (0,0) h = 0 when t is 0 and 4 (0,0) and (4,0)