# Posts by Damon

Total # Posts: 29,984

**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

**Physics 20**

A is 7620 m/s B is 2.71*10^20 kg and for heaven's sake use SCI units, do not use km and hours or something. Use meters, seconds, Newtons, kilograms. 1 hour = 3600 seconds 1 km = 1000 meters

**Physics 20**

B) v(9.06*10^3) = 2 pi (311) v = .216 m/s I do not think so, suspect you mean 311km not 311 m that would give v = 216 m/s then 7620^2 = G Ma/r 7620^2 = 6.67*10^-11 Ma/311 Ma = 2.71*10^20 kg

**Physics 20**

v^2 = G Me/r v^2 = (6.67*10^-11)(5.97*10^24) /6.85*10^6 v^2 = 5.81 * 10^7 = 58.1*10^6 so v = 7.62*10^3 so v = 7620 meters/second

**Physics 20**

A)when in orbit about earth mv^2/r = m (G Mearth)/r^2 solve for v B) same equation but get v immediately v T = 2 pi r then m v^2/r = m Ma(G/r^2) m , mass of sat cancels we know v solve for Ma

**Physics 20**

I did B

**Physics 20**

Weight is NOT in kg but in Newtons !!!!!! F = m * 9.81 = 154*9.81 = 1510 Newtons

**Physics 20**

A) F = G m Me /r^2 at surface G Me/r^2 = 9.81 B) answer to A*r^2/(r+222,000)^2 but if you try to measure it with a scale, zero because F is balanced exactly by mv^2/R if in orbit which is the answer to part C. Really weight in orbit means nothing.

**Physic**

x = 1.6 (pi)cos(pi*1.3 +pi/3) = 5.03 cos (1.63 pi) = 5.03 * .397

**Algebra**

(A/2) -5 = 35 A/2 = 40 A = 80

**Health**

yes. Despite the act that it ends in s, it is one disease.

**Physics 20 Energy**

m g (change in height) 85 * 9.81 * 2.4 *1000 Joules

**Physics 20**

5(2.5)^2 =5*6.25

**huh??**

It is a four dimensional pool?

**Chemistry**

H2O = 18 g/mol so I have 5.5/18 mols water you get two mols H2O for every mol of O2 so I used 5.5/36 mols O2 O2 = 32 g/mol so 5.5*32/36 = 4.89 grams O2

**Chemistry**

Fe2O3 + Al ---> Al2O3 + Fe same number of mols of Fe as of Al Al = 30 g/mol so 225/30 mols of Al so 225/30 mols of Fe so (225/30) mol mass of Fe (225/30)56 = 420 grams of iron

**Nope**

Look at it on a number line. for positive x-3 x must be to the right of 3 but then sqrt x must be greater than sqrt (x-3) which is not possible. If it were -3 on the right, that would be different (x-3)^.5 - x^.5 = 3 square both sides [(x-3)^.5-x^.5][(x-3)^.5-x^.5] = 9 (x-3)-2...

**Physics 20 Gravity**

11.2 m/s^2 as compared to 9.81 on earth

**Physics 20 Gravity**

g = F/m = G M/r^2 where G = 6.67*10^-11 M = 7.66*10^24 r = 6.74*10^6

**English**

maybe something like: Increased government subsidies would make US manufacturers more competitive with heavily subsidized foreign industries.

**Algebra**

height/shadow = 3.4/1.73 = h/48.25 so h = (3.4/1.73)48.25 which is 3.4 * 48.25/1.73 or 94.8 Draw a picture !!!!

**maths help plz sir damon steve or reiny**

This might help: http://tutorial.math.lamar.edu/Classes/DE/HOVariationOfParam.aspx

**whoops**

825/10,000 or 33/400

**Algebra**

8.25/100 = 825/1000 divide top and bottom by 25 to get = 33/40

**Algebra**

.06*$70 = $4.20 it is supposed to be in dollars accurate to the penny

**Algebra**

120-84 = 36 (36/120)100 = 30%

**Math**

[ (7/3) +2 ] /[-3 -(3/2)] (13/3) / (-9/2) = -26/27 I get B

**chemistry**

I suppose w is weight? I suspect you mean mass in grams water is about 1 gram/cm^3 or 1 kilogram/liter so our NaCl here is .075*1 = .075 kg per liter or 75 grams/liter so the real question is How many mols is 75 grams of NaCl NaCl = 58.5 grams/mol (23+35.5) so 75 g (1mol/58.5g...

**algebra**

7/3 = 2 1/3 or 2.33333.......

**algebra**

0.164*188 = 30.8

**Physics**

h = 20 + .4 t - 4.9 t^2 solve for t when h = 0 just like the problem you posted below this one. also the speed when it hits the ground is the same method.

**Physics**

h = 1.5 + 2.5 t -4.9 t^2 when is h = 0? solve quadratic for t 4.9 t^2 -2.5 t - 1.5 = 0 you could use http://www.math.com/students/calculators/source/quadratic.htm Note, quadratics have two solutions of course. In this problem if you get a neagative time, that is how long ago ...

**Physics**

d = 13.9 * .6 + (13.9/2)t because average speed during deacceleration = half the original speed time to stop during acceleration is t: v = Vi + a t in general so 0 = 13.9 - 3 t t = 13.9/3 so in the end d=13.9*.6 + (13.9/2)(13.9/3) part b will you go 35+9.5 meters in time? what...

**Physics**

a)assume you mean Vx=1.4t^2+1.1t v = 1.4(16) + 1.1(4) b) change in velocity = answer to part a since velocity at t = 0 was 0 so divide a the answer to part a by 4 seconds

**Oh, use Reiny reply**

I did not see the reversal of direction

**Physics (typo?)**

30 min = .5 h 10 min = 1/6 h 20 min = 1/3 h ================= d = 140*.5 + 90/6 + 90/3 (it went 90 for a total of 1/2hour???? typo I bet) average speed = d /total time the way you wrote it the total time is one hour, but I doubt it.

**science doppler to and fro**

what frequency does the blood hear? for observer toward source: f' = f (v+Vobserver)/v f' =6.113*10^6(1570+.3979)/1570 calculate f' the blood particle serves as a transponder sending back a signal at that f' now the source is moving toward the observer f"...

**Physics**

for speed divide the distance by the time for velocity divide the DISPLACEMENT by the time displacement is a vector with x y and perhaps z components. All the way around a track is a Distance of 2 pi r BUT a displacement of ZERO

**science chemistry**

Particles maintain their distance and orientation to other particles in the solid state and only vibrate a little in place so the shape and volume of a lead block does not change (much:). In the liquid state, the particles maintain their distance but not orientation so the ...