# Posts by Damon

Total # Posts: 29,823

**Trig**

cot = 1/tan = cos/sin csc = 1/sin so cot = csc*cos cos = sqrt(1-sin^2) cot = 3.589142*sqrt(1-1/3.589142^2) =3.447019 or 3.45

**physics**

1.38*2pi radians/s = 8.67 8.67^2(.139) = 10.4 m/s^2 or about one g Humm, why not leave it sitting in the collander ?

**physics**

Va^2/140 =Vb^2/295 Va^2/Vb^2 = 140/295 Va/Vb = sqrt(140/295)

**physics**

distance = 2 pi r = 2 pi*2660 meters speed v = 2 pi 2660/200 meters/s Ac = v^2/r

**Algebra 1**

-3x + 2y = +11 +3x - 4y = -19 --------------- add 0 -2 y = -8 y = 4 then -3 x + 8 = 11 3x= -3 x = -1

**Geography please help**

Usually associated with Buddhism but also is part of Hinduism

**science**

one mol of H2S for every 2 mols of HCl 2.56/2 =1.28 That assumes of course that you put in plenty of Na2S

**MATHS**

http://www.purplemath.com/modules/triggrph2.htm

**Physics**

Gave rough beat frequency response below.

**Social Studies**

So I guess "mother of waters". They may not have been familiar with the bleak ocean :)

**Social Studies**

maybe for meaning: http://en.wikipedia.org/wiki/Sarasvati_River

**Very hard math**

.15*75 = 11.25 sure enough

**Physics**

Look mainly at the low "beat" frequency. 4sin96pit + 8(sin 100pit +sin99pit) 4 sin96pit +16 sin100pitcos4pit saying 199/2 is about 100 that is about 4 sin 100 pi t [1+ 4cos 2 pi t] the low beat frequency is max when 2 pi t = 0, 2pi, etc min when 2 pi t = pi/2, pi/2...

**math.......**

distributive property of multiplication price = x tax = 0.05 x which is 5%/100 of x 1 x + .05 x = (1+.05) x = 1.05 x

**Math (Octants identifying) *emergency***

Like here: http://en.wikipedia.org/wiki/Octant_(solid_geometry)

**Math (Octants identifying) *emergency***

1,1,1 1,1,-1 1,-1,1 1,-1,1 -1,1,1 -1,1,-1 -1,-1,1 -1,-1,-1 are all in different octants you need the sign of x y and z. They are called octants because there are 8 of them. Draw a picture.

**physics**

say the water is moving in x direction at 4 km/h say we swim in y direction at 3 km/h then our speed is sqrt (3^2+4^2) = 5 km/h tan angle above x axis is tan theta = 3/4 = .75

**chemistry**

1200 mg /200 = 6

**Physics**

if you want the compass angle east of north, it is 90 - that

**Physics**

North 150 cos 60 = 75 km N East 150 sin 60 - 100 = 29.9 km E distance = sqrt(75^2+29.9^2) tan angle north of east = 75/29.9

**calculus**

No need for L'Hopital 16-x^2 = (4-x)(4+x) so you really have: (4-x) at x = -4 4-(-4) = 8

**enough**

You are wasting your time and ours. Please take the course before you try to do the problems.

**Trigonometry with right triangles**

If you were taking geometry, you would be in serious trouble.

**Trigonometry with right triangles**

He did not understand my reply to the last question either. He clearly has not studied the material yet.

**Some basic concept of chemistry**

http://www.lagoonsonline.com/laboratory-articles/normality.htm

**Physical Sciences**

Google diamond. I think you will find that it is pure Carbon, C. The carbon atoms are arranged in a crystal structure under high temp and pressure.

**Pseudocode**

20*1.05 = 21 or do it the hard way 20*1 + .05*20 = 20 + 1 = 21 note use of distributive property to do it fast.

**geometry**

1-s)(1+s) 1-s^2 1-sin^2x = cos^2x cos^2x + cos^2 (sin^2x/cos^2x) = cos^2 x + sin^2 x = 1

**how far behind?**

truck goes 20 t car goes 50 t 50 t - 20 t = distance behind in kilometers resulting t is in hours multiply by 3600 to get seconds

**math**

--- 1 2 3 4 5 6 1========1,4 2 =====2,3 3 ==3,2 4=4,1 5 6 four out of 36 = 1/9 that is one out of every nine so a once b twice c three times d 100/9 = about 11 times e 450/9 = 50 times

**Math!!!!**

You are welcome.

**Math!!!!**

Well, you do not build each piston for each cylinder. You order the piston from the auto parts store for your type of engine. It better be the same size and shape as the old one or it either will not fit the cylinder or the connecting rod or the piston rings.

**Math!!!!**

Ah, pistons in your car engine?

**Math**

links in your bike chain?

**Geometry/Trig**

tan 80 = 18/x so x = 18/tan 80

**Dating with Radioactivity**

I am not geologist but question: 3. Upside down? 4. If there is sand in the granite did the sand not already exist when the granite formed? 5. Not at all sure 7. I suspect rapid burial but read your text about it.

**Geometry / Trig**

well, we need the area of an equilateral triangle with sides of one cm. Then we multiply by six for altitude sin 30 = (1/2)/1 cos 30 = h/1 h=.866 so area of triangle = (1/2)(1)(.866) = .433 then multiply by six 6*.433 = 2.6 cm^2

**8th grade math /lesson3/functions**

Those are all arithmetic sequences above 7. is correct

**8th grade math /lesson3/functions**

up TEN each time 39,49,59

**8th grade math /lesson3/functions**

3*1+5 = 8 3*2+5 = 11 3*3+5 = 14

**8th grade math /lesson3/functions**

In the first one, subtract 8 each time so -2, -10 , -18

**math**

0.60 x = 372 so x = 372/0.60 = 3720/6

**Science**

Way too much H2 H2O = 2 + 16 = 18 grams/mol that is 16 g/mol of O so 8 g is 1/2 mol of O H2 is 2 g/mol so 5g is 2.6 mol, more than we need so we end up with 1/2 mol of water which is 9 grams

**CHECK answers science**

Yes. I might argue about #3 because Thompson's "plum pudding" model was pretty crude compared to Rutherford's model, but Thomson did have sub atomic particles.

**error**

last two lines d = 4.9 t^2 = 2.33 meters

**physics**

average speed passing window = -2 meters/.25 s = -8 ms constant acceleration = -9.81 m/s so while crossing the window v = Vi -.981t change in v while crossing window = -9.81*.25 = -2.4525 m/s half that = -1.23 m/s so v at window top = -8+1.23 = -6.77 m/s so how far did it fall...

**Physics**

but then 1 second * initial speed + (1/2)(4)t^2

**Specify a Period on the graph**

see question below this one.

**Calculus**

when is 5 pi x = 2 pi ???? x = 2/5

**Math**

8+8 + x+x = 26 2 x = 10 x = 5 but you have a typo no doubt I bet the perimeter is 260 yards.

**physics**

Law #1 momentum of passenger continues forward until acted upon by windshield or other force.

**physics**

Well, lots of things can happen but what you can count on is conservation of momentum of the overall runner, tackler, ground system. Any forces from the ground on the people can change the momentum of the merged runner-tackler system. If they were both on ice and ran into each...

**Math**

4 2/3 = 14/3 divide by 5 14/15

**Calculus**

If it is a horizontal line the slope is zero. y = a constant (y-y1)/(x-x1) = 0 y - y1 = 0 y = y1 put in the given y y = -9

**Yoruba**

If you just want the word for sun: http://www.wordhippo.com/what-is/the/yoruba-word-for-22fa6121da96f43a106e413e65d4f9089c53824c.html

**Geometry**

http://www.calculatorsoup.com/calculators/geometry-solids/cone.php

**Geometry**

do not do that Lillylove volume of sphere = (4/3)pi r^3

**School**

oh my, schools, unions, Planned Parenthood .....

**School**

Yes, I bet she was very busy. http://democracywise.syr.edu/?p=3939

**School**

I do not see anything written about her in the last couple of days, but judging by her history in government I bet she had a very busy weekend, perhaps in Washington.

**School**

Councilor at large, Syracuse, NY ? Google her name

**Math**

You are welcome.

**Math**

60% of them :) .6*70 = 6*7 = 42

**algebra**

should look like 11 x^2 - 28 x -480 = 0 (11x+60)(x-8) = 0

**you try first**

This time you try first and show work. Same method.

**math**

aaarrrrggh too many of these, use: http://www.mathsisfun.com/algebra/sequences-sums-arithmetic.html

**author?**

Try to google story "knife" LOL

**math**

straight up and down, (Y2-Y1)/(x2-x1) = (Y2-Y1)/ 0 undefined

**math**

compounds 24 times a year so r = .03/24 = 0.00125 per period 25 years = 25*24 = 600 periods A = 10,000 * 1.00125^600 = 10,000 * 2.116008731 = $21,160.09

**Science**

6 volt battery resistance of 8 ohms I assume the resistors are also in series i = 6/8 = 3/4 = 0.75 amps

**algebra**

x^2 + (x+6)^2 = (x+12)^2 x^2+ x^2+ 12 x + 36 = x^2 +24 x +144 x^2 - 12 x - 108 = 0 108 is 6*18 for example (x-18)(x+6) = 0 try x = 18 then x+6 = 24 and x+12 = 30 ===================== check 18^2 + 24^2 = 30^2 ???????? 324 + 576 = 900 whew !

**Ethics**

Actually from a maximum utility benefit/cost point of view, I should think B would be the winner.

**Geometry**

length scale = 4/17 area scale = 4^2/17^2 = 16/289 vol scale = 4^3/17^3 = 64/4913 x^3/y^3 = 1728/343 volume ratio x^2/y^2 = 576/y^2 area ratio x/y =(1728/343)^(1/3) = 5.0379^(1/3) = 1.7143 length ratio so x^2/y^2 = 1.7143^2 = 2.939 so 2.939 = 576/y^2 y^2 = 196 meters^2

**Geometry help**

You are welcome.

**Geometry help**

for anything with a pointed top and straight sides the volume = area of base * height *(1/3) so here the side^2*h is the same for each 14^2*24 = s^2*96 or 14^2/s^2 = 4 14/s = 2 s = 7

**Geometry help**

12*12*(9/12) = 108 ft^3 there are 3*3*3 = 27 ft^3/yd^3 108/27 = 4 cubic yards 4*54 = $216

**Chemistry**

Did the vapor pressure of this liquid change when you squeezed the gas down? I think not. Therefore the pressure did not change. You have half as many gas molecules above the fluid. Half the gas molecules condensed back into liquid form.

**HELP PLEASE**

Yes, exactly.

**Calculus**

f(3) = 0 f(0) = 9 slope = (0-9)/3 = -3 f' = -2x where is -2x = -3 ? x = 1.5

**Chemistry**

volume = 2.3 ml mass = 1.0107*10^-2 kg =10.107 grams density= m/v =10.107/2.3 = 4.39 g/mL maybe Titanium ?

**Chem**

3 * .25 * 6 * 10^23

**Chem**

You need 3 mol of A for every mol of B but you only have 2 mol A so you only use 2/3 of a mol of B that would yield 4/3 mol of C but we only got 1 mol of C 100 * 1/(4/3) = 75 % yield

**Math**

Take the average speed during each second times one second and add 6+9+8+7.5+10.5+8.5+6.5+9+8+9 = 82

**Chemistry**

grams/mol N=14 H=1 F= 19 so NH3 =17 F2 = 38 HF = 20 so If I have 4 g of NH3, how many g of F2 do I need? 4/[2(17)] = x/[5(38)] x = 20*38/34 = 22.4 g F2 whoops, not enough F2 so use 14 of F2 and y of NH3 y/34 = 14/190 y = 2.5 grams of NH3 then 2.5/34 = HF/[6(20)] HF = 8.82 ...

**pre algebra**

168 miles/3.5 hours = 48 mi/h

**Chemistry**

See below, I got 500

**Chemistry**

P V = n R T n is number of mols say we have 1 mol (n=1) of argon, 40 grams then we have 40 grams of Methane which is 40/16 or 2.5 mols (n=2.5) they both have the same V and T P/n = RT/V = same for each 200/1 = Pmeth/2.5 Pmeth = 2.5*200 = 500 torr

**Chem 112**

Zn = 65.4 grams/mol Cl = 35.5 grams/mol H = 1 gram/mol so 2HCl = 2(36.5g/mol) = 73 g ZnCl2 = 136.4 g/mol to get 1 gram ZnCl2 need (1/.684)(65.4/136.4)= .701 grams Zn

**Math**

original height = H h(t) = height dh/dt = -2cm/20min = -0.1 cm/min so h = H - 0.1 t h in cm, t in minutes

**phyisics**

You mean it stopped after 8 meters? If so average speed = (3+0)/2 = 1.5 m/s so t = 8/1.5 = 80/15 = 5.33 seconds sliding to a stop then acceleration a = (0-3)/5.33 = -.5625 m/s^2 so now the physics F = m a -m g (mu) = m (-.5625) mu = .5625/9.81 = .0573

**Calculus**

df/dx = -3 df = -3 dx |.05| = -3 |dx| |dx| = .01667 check if x = 1.01667 f(x) = -3(1.01667) + 2 = -3.05+ 2 = -1.05 distance from -1 is .05 sure enough

**chemistry**

answered this below

**chemistry**

2Mg + O2 ---> 2 MgO Mg = 24.3 g/mol O = 16 g/mol so 48.6 grams Mg + 32 grams O2 --> 80.6 grams MgO 5/80.6 = .062 mol MgO produced x/32 = .062 x = 1.985 grams O2 and we needed y/48.6 = .062 y = 3.00 grams of Mg sure enough

**chemistry**

if the masses are equal, the diamond has more volume because it is less dense.

**Math**

well, let's try the 20 on the bottom and the 15 sloping up toward the right. Try the diagonal connecting the two right ends. draw altitude h that divides the base into x and (20-x) x^2+ h^2 = 225 so h^2 = 225-x^2 (20-x)^2 + h^2 = 625 ----------------------- 400 -40 x + x^2...

**science**

original momentum = .04*500 = 20 kg m/s that will be the final momentum so 6 v + .04*200 = .04*500 6 v = .04*300 v = .04*50 v = 2 m/s

**Science**

Probably very hungry. They might not recognize the orchids as food. Many might die. I do not know anything about the relative nutritional value of cactus and orchid flowers. That would determine if a low surviving population would continue feeding on the few cactus plants or ...

**Finite math**

5 c + 7 s + 9 a = 6100 c + s + a = 900 a = .5 (c+s) or 2a - c - s = 0 ============================ add two and three 3 a = 900 so a = 300 c+s = 600 so s = 600 - c 3 c + 7 s + 2700 = 6100 3 c + 7(600-c) = 3400 3 c + 4200 - 7 c = 3400 4 c = 800 c = 200

**Physics 20**

No, the asteroid does NOT have a mass of 2.71 kg. That would be about the mass of a gallon or so of milk. I said 2.71*10^20 kg

**Physics 20**

READ A is 7620 m/s B is 2.71*10^20 kg