# Posts by Alan

Total # Posts: 382

**math**

I calculated the average number of crashes over a 240 week period to be .0875... what formula do I use to calculate the probability that at least 19 crashes would occur over that 240 week period?

*March 16, 2010*

**Physics**

A room has a volume of 120 m^3. An air-conditioning system is used to replace the air in the room every twenty minutes, using ducts that have a square cross ection. Assuming that air can be treated as an incompressible fluid, calculate the length of a side of the square if the...

*March 16, 2010*

**Chemistry**

Cu(NH3)2^+ is a colourless compound. Will there be any absorbance at 600nm?

*March 16, 2010*

**math**

h(x) = 1.95 x + 72.85 h(x) = 1.95(35) + 72.85 h(x) = 141.10

*March 16, 2010*

**apchem**

For a typical commercial vinegar with a 5% acetic acid content, the density is about 1.01 grams per milliliter.

*March 16, 2010*

**apche,m**

For a typical commercial vinegar with a 5% acetic acid content, the density is about 1.01 grams per milliliter.

*March 16, 2010*

**spelling**

The plural of family is families. So the first sentence is right.

*March 16, 2010*

**Chemistry**

What is the colour of: 1. Cu+ 2. Cu2+ 3. Cu3+?

*March 16, 2010*

**Chemistry**

Aspirin equilibrium is : HC9H7O4(aq) + H2O (double arrow)C9H7O4^-(aq) + H3O^+ You have 2 tablets each containing 0.325g of active ingredient that you dissolve in water up to 225ml. Calculate the pH.

*March 14, 2010*

**Math**

x + 2y =1 --- (1) 8x + 8y =4 --- (2) From (1), x + 2y = 1 x = 1 - 2y --- (3) Sub (3) into (2), 8 (1-2y) + 8y = 4 8 - 16y + 8y = 4 -8y = 4 - 8 -8y = -4 y = -0.5 sub y = -0.5 into (3), x = 1 - 2(-0.5) x = 1 + 1 x = 2 CHECK: sub x = 2 and y = -0.5 into (1), 2 + 2(-0.5) = 1

*March 14, 2010*

**math**

-6x + 3 =-7 - 5x -6x + 5x = -7 - 3 -x = -10 x = 10

*March 13, 2010*

**Physics**

energy of 1 photon = (Plank constant x speed of light, c) / wavelength = 6.626 x 10^-34 x 2.998 x 10^8 / 2 x 10^-1 = 9.93 x 10^-25 J energy of 10^12 photons = 9.93 x 10^-25 x 10^12 = 9.93 x 10^-13 J

*March 13, 2010*

**Chemistry**

What is the stoichiometric ratio for Cu2+ ions with cuprizone to form the copper-cuprizone complex?

*March 13, 2010*

**math**

average of: 8; 10; 12; 14; 16 = (8 + 10 + 12 + 14 + 16) / 5 = 60 / 5 = 12

*March 13, 2010*

**math**

x+8y=33 ---- (1) -x+4y=3 ---- (2) (1) + (2), x + 8y + (-x + 4y) = 33 + 3 12y = 36 y = 3 sub y = 3 into (2), -x + 4(3) = 3 -x = 3 - 12 -x = -9 x = 9 CHECK: sub x = 9 and y = 3 into (1), 9 + 8(3) = 33

*March 13, 2010*

**math**

6m+n=47 --- (1) m-4n=12 --- (2) From (2), m = 12 + 4n --- (3) sub (3) into (1), 6(12 + 4n) + n = 47 72 + 24n + n = 47 25n = -25 n = -1 sub n = -1 into (3), m = 12 + 4(-1) m = 8 CHECK: sub m = 8 and n = -1 into (2), 8 - 4(-1) = 12

*March 13, 2010*

**Chemistry**

Copper(I) Iodide is synthesised by the equation: 2CuSO4.5H2O + 2KI + 2Na2S2O3.5H2O --> 2CuI + K2SO4 + Na2SO4 + Na2S4O6 + 10H2O Would it make a difference if anhydrous CuSO4 and Na2S2O3 are used instead? Why hydrous CuSO4 and Na2S2O3 are used instead?

*March 13, 2010*

**Chemistry**

What is the stoichiometric ratio for Cu2+ ions with cuprizone to form the copper-cuprizone complex?

*March 13, 2010*

**Chemistry**

How should I write the balanced chemical equation to represent the oxidation of Cu+ ion by air? [Cu(NH3)3]^+1 + 2H2O + ??? --> [Cu(NH3)3(H2O)2]^+2

*March 13, 2010*

**Chemistry**

Can [Cu(NH3)2]^+ and/or [Cu(NH3)3]^+ be oxidised by air to become [Cu(NH3)2]^2+ and [Cu(NH3)3]^2+ respectively?

*March 13, 2010*

**Chemistry**

What would be the most likely product(s) when you react CuI with NH4OH?

*March 13, 2010*

**Chemistry**

What is the chemical equation for: CuI + NH4OH ---> ??? This equation should oxidise Cu+ to Cu2+.

*March 13, 2010*

**Physics Tough question!**

o wow, i didn't even think of the geometrical way, thanks.

*March 8, 2010*

**Physics Tough question!**

A pond has the shape of an ice cream cone with the tip slices off and has a depth of 5.00m. The atmospheric pressure above the pond is 1.01 *10^5 Pa. The circular top surface (radius = R2) and circular bottum (radis = R1) of the pond are both parrallel to the ground. The angle...

*March 8, 2010*

**Physics**

Also, teacher gave me a hint that "r(radius)" was suppose to cancel during the formula manipulation process..

*March 3, 2010*

**Physics**

A hypothetical spherical planet consists entirely of iron (p=7860 kg/m^3). Calclate the period of a satellite that orbits just above its surface. I started out with the density formula P=M/V, but i kept subbing in other formulas, but i get stuck..can someone help me? thanks. I...

*March 3, 2010*

**Physics, help please!**

Im sorry! I meant density! It was represented by a small p, so i thought pressure >_< Anyways, density = mass/volumne. My teacher gave me a hint about radius cancelling each other off in the formula manipulation. Hope this helps!

*March 2, 2010*

**Physics, help please!**

A hypothetical spherical planet consists entirely of iron (p=7860 kg/m^3). Calclate the period of a satellite that orbits just above its surface. I started out with the pressure formula P=M/V, but i kept subbing in other formulas, but i get stuck..can someone help me? thanks.

*March 2, 2010*

**Physics**

A hypothetical spherical planet consists entirely of iron (p=7860 kg/m^3). Calclate the period of a satellite that orbits just above its surface. I started out with the pressure formula P=M/V, but i kept subbing in other formulas, but i get stuck..can someone help me? thanks.

*March 2, 2010*

**Physics**

Thanks

*February 16, 2010*

**Physics**

A 3.00 uF and a 5.00 uF capacitor are connected in series cross a 30.0V battery. A 7.00 uF capacitor is then connected in parallel across the 3.00 uF capacitor. a)Calculate the equivalent capacitance of the circuit I think the answer is 3.33 uF. b)Determine the voltage across ...

*February 16, 2010*

**Chemistry**

What are the possible side reactions for this case?

*February 12, 2010*

**Chemistry**

I recently did an experiment on Aldol Condensation, by reacting Benzaldehyde with Acetone to form Dibenzalacetone. The proposed stoichiometric ratio of Benzaldehyde:Acetone is 2:1. What would be the implications if either of the reactants is in excess?

*February 12, 2010*

**Phyics**

Thanks a lot!

*February 10, 2010*

**Phyics**

A resistor has a resistance R, and a battery has an internal resistance r. When the resistor is connected across the battery, ten percent less power is dissipated in R than would be dissipated if the battery had no internal resistance. Show that the ratio r/R is equal to 0.054...

*February 10, 2010*

**Geometry**

What is the sum of the measures of the interior angles of a convex octagon? What is the sum of the measures of the interior angles of a convex decagon? What is the measure of one interior angle of a regular polygon with 20 sides? Thank You! (:

*February 3, 2010*

**math**

Isolate x or y in either equation and then subsitute it in to the other equation. x+y=56 x=56-y Subsitute into the other equation: Since x=56-y, the other equation becomes (56-y)+3y=56 56+2y=56 subtract 56 from both sides 2y=0 y=0/2 y=0 then x must be 56

*January 21, 2010*

**physics**

It decreases very very slightly. Mabye from 9.81m/s^2 to 9.80m/s^2, MABYE. Depending on how far you travel away from Earth, the force due to gravity is decreases exponentially. This can be proven with Fg=Gm1m2/r^2 where G=Gravitational constant(6.67*10^-11 N*m^2/kg^2)

*January 21, 2010*

**Math**

Ooo right, my teacher mentioned that, guessed it slipped my mind. Thanks a lot. Diploma tomorrow :(

*January 21, 2010*

**Math**

Log(base a)(a^4*b)-Log(base a)(a*b) is the same as a)4 b)3 c)3a d)a^3 I got the answer as d since subtracting logs with the same base is division. However, the answer key saids its b, Can someone please help me with this?

*January 21, 2010*

**math**

5 divided by 3, gives you 1.6666666666667 gallons of punch per bowl. In fraction form, it would 5/3 gallons per bowl.

*January 21, 2010*

**Chemistry**

Calculate the volume occupied by 18g of water vapor at 100C at 1 atm. Show calculations

*December 12, 2009*

**algebra**

well, i didn't think of that, if that's the case, v=(-1/3)t+4 Sub in t=6 v=(-1/3)(6)+4 v=(-6/3)+4 v=-2+4 v=2 Hope you read this before you sleep =\

*December 7, 2009*

**algebra**

Sub in t=6 into the formula v=-1/3t+4 v=-1/3(6)+4 v=-1/18+4 v=-1/18+72/18 (4 is the same as 4/1 and when multiplied by 18, 72/18) v=71/18

*December 7, 2009*

**Science**

B) Fault block mountains Happens when two plates collide, and force the rock up.

*December 7, 2009*

**algebra**

if you rearrange the question it becomes y=8x-8 Using y=mx+b, with m as your slope, your slope is 8

*December 7, 2009*

**Physics**

huh....

*December 7, 2009*

**Physics**

I typed exactly what is said on the question sheet. Answer given is 5.47*10^15 photons/s As each photon strikes the electron, it is absorbed and then any excess energy is then re-radiated in the form of x-rays, from what i understand, i need to find the remaining energy (since...

*December 7, 2009*

**Physics**

A cathode ray tube operates at 80 kV with a current of 875 uA. Calculate the a)Intesity (# of photons per second f the x-rays b)Minimum wavelength of the x-rays produced by the CRT thanks in advance

*December 7, 2009*

**Physical Science**

W=FD W=(400N)(3.0m) W=1200N I don't really get the 1250N car thing. Unless you also need friction, but i need the coefficent for that.

*December 7, 2009*

**Algebra**

Using the point slope formula m=(y2-y1)/(x2-x1) m=([1/2]-[1/2])/([-5]-[-9]) m=0/4 m=0 In other words, this is a horizontel line, with a slope of 0 m=rise/run

*December 7, 2009*

**Physics**

Yes, if the particle is not in motion, it will not experience a magnetic force (faraday's law) Yes to 2 too, using the third hand rule, fingers pointing in the direction magnetic field (north to south), thumb pointing in the direction of particle movement(in this case ...

*December 7, 2009*

**Physics**

Information you have: m=23kg Fg(1)=185N Using the Fg=mg, you can figure out the force exerted on the suitcase by gravity if there was no force pulling it: Fg=mg Fg=(23kg)(8=9.81m/s^2) Fg=225.63N Fg-Fg(1)=F experienced by handle 225.63N-185N=40.63N

*December 7, 2009*

**math**

Perms question Since there are 8 students, you say 8! or 8 factorial 8*7*6*5*4*3*2*1 8 first because there are 8 possible choices, 7 for the next one since one student has already been chosen, and so on. Answer is 40320

*December 6, 2009*

**physics**

Brightness also refers to intensity, or # of photons, what determines the kinetic energy of the ejected electrons is frequencey, as each photon releases 1 electron, if the photon has enough energy to overcome the work function, the remaining energy is then transformed into the...

*December 5, 2009*

**12th grade**

This is probably waaaaay to late, but period can be determined using b=180/p b=3 period is 60

*November 15, 2009*

**Physics 30**

Thanks

*November 11, 2009*

**Physics 30**

I got stuck after i attempted to use 1/f=1/di+1/do, seeing as how i need di, which i don't have.

*November 11, 2009*

**Physics 30**

An object located in front of a concave mirror with a radius of curvature of 80 cm produces an invert image that is three times the size of the object. Calculate the distance between the object and the mirror.

*November 11, 2009*

**Physics**

A 75 g autographed baseball slides off of a 1.3 m high table and strikes the floor a hori- zontal distance of 0.65 m away from the table. The acceleration of gravity is 9.81 m/s2 . What was the direction of the ball’s velocity just before it hit the floor? That is, at ...

*November 9, 2009*

**Physics**

What was the direction of the ball’s velocity just before it hit the floor? That is, at what angle (in the range −90◦ to +90◦ relative to the horizontal directed away from the table) did the ball hit the floor? Answer in units of ◦.

*November 9, 2009*

**Physics**

I have the same problem and I can't figure it out the answers on these forums are useless

*October 21, 2009*

**social studies**

229423s8182

*October 18, 2009*

**College Algebra**

Mendoza Manufacturing plans to producea one compartment vertical file by bending the long side of a 10-in. by 18-in. sheet of plastic along two lines to form a U-shape. How tall should the file be in order to maximize the volume that it can hold?

*October 4, 2009*

**Math**

yes it is take 30 times 7865 and you get 235950

*October 4, 2009*

**3rd grade**

An big idea would end in a huge result and also could take a lot of other accomplishments to get to it. A small idea is easy to obtain over a short period of time. An example is a sports team. If they have the goal of winning the state tournament at the end of the year they ...

*October 4, 2009*

**Global History**

Identify Jacobins

*September 28, 2009*

**sociology 120**

I need help with today's assignment in intro to Sociology120. The assignment is urbanization trends

*August 21, 2009*

**math**

we square all and evalaute as a diff of 2 squares

*August 16, 2009*

**Psy 230 Theories of Personality**

Use Appendix b to list at least five of the events or major concepts in each of the three historic periods of personality psychology.

*July 18, 2009*

**Literacy**

I don't exactly live in america, but im in year 5, which i think is grade 5 in america. But i have a really desperate question i need to ask.... When a word ends in "Phobia" what kind of word is it? is it a noun, adjective verb? can you please tell me?

*June 2, 2009*

**Chemistry**

This is the last one Dr Bob! How much concentrated 18 M sulfuric acid is need to prepare 250 ml of a 6.0 M solution? Im stumped again, could you point me in the right direction ? Thank you sir!

*May 28, 2009*

**Chemistry**

How much concentrated 18 M sulfuric acid is need to prepare 250 ml of a 6.0 M solution? This is the last one guys, its got me stumped again =)

*May 28, 2009*

**Chemistry**

What is the molality of a solution made from 5.61 moles of KCl and 2.11 kg of water? I'm very lost on this one, could someone please help me?

*May 28, 2009*

**finance**

answer to your question you take collection cost 5% of new sales which is 4,000 add 16,000 which is your a/c fiqure you got sales divided by a/c turnover which equal 20,000 which is your inventory..

*May 13, 2009*

**MATH**

A simple ratio can be used 18 45 --- = --- X 60 18 x 60 ------- = 24 pages 45

*May 10, 2009*

**Term paper**

So I could word it.. Nearly every country of the world uses some method of hydroponics, either on a small or large scale.

*May 10, 2009*

**Term paper**

Nearly every country of the world uses some method, either on a small or a large scale , of hydroponics. Is this written correctly? Does any one want to help me proof read my term paper?

*May 10, 2009*

**Spanish**

eodns These are the letters to a spanish word what does it spell?

*April 30, 2009*

**History of English Economics**

What kind of Cammand is China

*April 15, 2009*

**Term paper Research**

i don't know if you remember me. But I am the one that is doing the term paper over hydroponics. I have found a couple of really good sites thanks to one of the homework helpers. but i really need magazine articles about hydroponics. I have found a couple of text books I ...

*April 5, 2009*

**Spanish**

WRONG

*April 5, 2009*

**Spanish**

It is not my eyes look incredible terms: snow on the almond bloom snow on snow. This winter my mood is like an early spring, is like an almond tree in bloom under the snow. There are too cold this evening in the world. But I open the door to my dog and he comes home heat ...

*April 5, 2009*

**8th grade**

Drive a car around a big circle track.

*April 2, 2009*

**Algebra**

see michelle's answer

*April 2, 2009*

**Algebra**

(1) ------------- 25x^2 + 22xy - 3y

*April 2, 2009*

**Algebra**

take the interest rate divided by (100 times the compounded) add one take that answer to the (number of years times the compound) multiply this entire total times money times dollars invested

*April 2, 2009*

**Pre Algebra**

what are you asking??? i think i might know but make it more clear.

*April 2, 2009*

**vocabulary**

Whats an word for everyday language? not english. a vocab term

*March 30, 2009*

**Everyone read!!!**

Well its great to hear that your not a part of an illegal indoor hydroponics but thank you Ms. Sue for the websites they helped a lot and drwls your answer gave me ideas for my paper. Its not due till the end of April. Thanks all and if anyone has any other ideas go ahead and ...

*March 25, 2009*

**Everyone read!!!**

I have to write a term paper for two classes. the teachers are letting us students write only one but the topic has to be scientific. It is going to be 10-12 pages long double spaced. I was thinking Hydroponics but I am worried that I might get bored after 5 pages... Any ideas...

*March 25, 2009*

**social studies/history**

Who was the first president to state the inauguration and how old was he at the time?

*January 21, 2009*

**finance**

If exchange rate depreciate, what will happen to the parent company NPV of foreign cashflow?

*January 10, 2009*

**Global**

Who Was Affected By the Historical event In The medieval time

*January 2, 2009*

**American Literature**

I amd writing a paper over how mark twain uses satire to criticize religion. My opening statement is: Helping a slave runaway and floating down the Mississippi river accompanied by two conmen appears to be the basis of a real adventure tale. My teacher has asked me to ...

*December 17, 2008*

**History Paper**

My summary is over an article about the battle of Khe Sanh, shoe i have my interduction begin with statistics of the end of the battle to attract readers and build up to the thesis or begin with my thesis about the major contreversory behind the battle and focus on it.

*November 20, 2008*

**Need many responses**

I have a history teacher that wants a paper over my article explaining who , what , when, where, why and how. The fact is these articles are short and two students turn in 3 paragraphs for a summary. . . long summary. and was given another page worth of info needed to add in ...

*November 20, 2008*

**grammar**

The lion said to hare. Ah you have come at last

*November 9, 2008*

**Physics**

807.4 N ?

*October 10, 2008*