Homework Help

THe questions states: Using the locus appraoch(definition) of the hyperbola to write the equation of the hyperbola with centre (o,0) foci (17,0) (-17,0) and difference of the focal radii 30. How do i solve this?

hey guys, can u help me with these 3 questions? 1. Naphthalene combustion can be used to calibrate the heat capacity of a bomb calorimeter. The heat of combustion of naphthalene (C10H8) is 40.1kJ/g. When 0.8210g of naphthalene was combusted in a calorimeter containing 1000g water, a temperature rise of 4.21 degrees C was observed. What is the heat capacity of the bomb calorimeter excluding the water? (What i've got so far is that since heat of combustion is 40.1 kJ/g, so 401 x 0.8210 = 329.221kJ must have been released by naphthalene. Next i think i should use q = ms(delta T) except i'm not sure how we're meant to find the heat capacity of the bomb calorimeter "e…

can i have some confirming plz? 1. The vapour pressure of pure water at 25 degrees c is 23.8 mmHg. Determine the vapour pressure of water at 25 degrees C above a solution containing 33.2 g of urea (a nonvolatile, nonelectrolyte, MW = 60g/mol) dissolved in 75 g of water. (i found no. of moles of urea = 0.5533 and no. of moles of water = 4.1667. since P(solution) = x(solvent) x Pure pressure (solvent), P(solution) = 21.01 mmHg.) does anyone agree with my answer?) 2. Calculate the reaction enthalpy in kJ for the formation of anhydrous aluminium chloride 2Al(s) + 3Cl2(g) --> 2AlCl3(s) from the data: 2Al(s) + 6HCl(aq) --> AlCl3(aq) + 3H2(g) delta H…

Well to begin . I'm crap at maths and I have a test after the weekend is over , I didn't turn up to maths class the other day and now I missed out and forgot what I'm supposed to know about in/equations . darn . If anyone can spare a little time explaining to me how I'm suppose to approach : Simultaneous Solutions Gradients intercepts With an example to use : inequation : 3x-5y<15 and equation : 2t-4c=11 It would very nice of you .. thanks heaps in advance

Oh boy here we go....writing straight line equations from y=mx+b to standard form (Ax+By+C=0) y=mx+b i know that y=-1/2 m=1 and x=4 .:. -1/2=(1)(4)+b -1/2=4+b find common demoninator and multiply it by all 2(-1/2) = 2(4)+2(b) -1=8+2b isolate b -2b=8+1 -2b=9 b= -9/2 as a rule though....no fractions in final answer get everything on one side 0=x-y-9/2 common demoninator, multiply it by all 2(0)=2x-2y-2(9/2) 0=2x-2y-9 just switch so =0 is on right side....neater 2x-2y-9=0 Eh? Did I do it right...I think I did....this is how we were taught...sorry it's long I know....

Dialysis tubing is a transparent, selectively permeable layer. It is artificial. If we pour some sucrose solution into it, the sucrose molecules cannot escape as they are too big to do so. What happens if we boil the dialysis tubing? I think sucrose cannot pass through the layer either since the layer does not consist of living tissues/cells which contains living cell membrane destroyed the heating. Am I correct?

please couldsomone help me on my problems in the math forum. noone has actaully helped me, and help i need. so please check out my thread in math, thank you those who respond.

Hi! I am an 8th grade honors science student. I have to do a project in which I create an animal capable of living on another planet. lucky me, i got venus (220mph winds, 800degrees f, sulfuric acid clouds, who wouldn't want to live there? ) We have to find a way for it to eat, breath, and deal with the surroundings. I was planning on having it eat the microbes they believe may live in the atmosphere. if anyone has any suggestions, in plain english when possible, i would appreciate it. thank you!

Hey, if anyone reads this within the next hour could you please help What class of organic compound is hydrolised in aqueous acid to produce a carboxylic acid and an amine? a acetal b ester c imine d anhydride e amide i thought it might be b but im still unsure please help t

hey guys, can u help me with these few questions? 1. In the molecule below, which carbon atom is in the highest oxidation state? BrCH2CH(OH)CH(OH)C(=O)CH2C(=O)OCH3 (I have NO idea of what to do!!! Can any1 help me?) 2. In the reduction of carbonyl compounds with LiALH4, the effective reducing species is: (a) Li+ (b) Al(3+) © AlH4(-) (d) AlH3 (e) H- (i think the answer is c...any1 agree?) 3. What is the IUPAC name for the following compound? CH3CH2CH2CH(Cl)C(=O)Cl (a) 1-chloropentanoyl chloride (b) 1-chloro-1-butanoyl chloride © 2-chloropentanoyl chloride (d) 1,2-dichloropentanal (i think the answer is c...wat do u guys think?)

hey can anyone confirm whether i've got the name of this organic compound right? CH3CH(Br)CH(CH3)CH2CH(phenyl)CH2CH3 is it 2-bromo-3-methyl-5-phenylheptane? (or is it 6-bromo-5-methyl-3-phenylheptane?)

hey guys can u help me/confirm these 2 questions? i've attached them (their just pictures of the questions that i took with a digital camera - coz im not sure how to just put an image in *blush)..hopefully the attachments worked

Hey. I just need some help on coming up with an original idea for a science fair project. I don't know where to begin. I need a topic asap. I would really appreciate the help.

60 L of a gas were collected over water when the barometer read 670mmHg, and the temp. was 20C. The pressure of H2O vapor at 20C is 17.5 mmHg. What volume would the dry gas occupy at standard conditions? I used the rearranged equation: V2=T2xP1xV1/t1xP2 and got 2329.5 L. Is that correct??Any help would be appreciated. Also, what gas equation is to be used to answer this problem: N2 occupies a volume of 600mL at 60C and 650mmHg of pressure. What will the volume be at STP??

1. How am i supposed to found out how much of a certain molecule is needed to neutralize another molecule? ie. "How many milliliters of .400 M KOH will neutralize 25 mL of .600 M H2S04?" 2. How do i find out the molarity and concentration of a molecule in a solution? 3. What salt is produced from the reaction of H2SO4 and KOH? ("is it K2SO4?") Thanks for your replies. If you are going to reply...

I have a question about truth tables for the logic gates. I am given the truth table, I have to work out what the circuit would look like and what the function of the logic gate is ... like I have to find out : x = a.b.c + a.b + c that was just an example.. Now this is the truth table i am given: A B C Output 0 0 0 0 0 0 1 1 0 1 0 1 1 0 0 1 0 1 1 0 1 0 1 0 1 1 0 0 1 1 1 0 Would anyone be able to tell me the function of this truth table, or tell me the diagram of the setup of the combined logic gates, i think it SHOULD be used with AND OR and NOT gates combined.

I need an idea for an earth science research project idea by the end of this week, that can be done within 3 weeks. Requirements -Must be a research topic -Must be at High School level (grade 10 and up) Thanks for the help. -Hoffman

[ post erased ]

I have to do a small speech on racism on Wednesday. The topic is: "To what extent do you think racism still exists in America today? How has racism changed over the years. Stat examples and possible causes of racism today." I haven't been able to find any information on the subject. I've tried Google but there wasn't anything useful. I need some information or a link to some soon. Thanks in advance. I'm going to go try a different search engine now...

Can any1 tell me if CrO4 (2-) is the formula for a chromate ion? Also, does any1 know the wavelength of it or the colour of light it absorbs? (I've looked on the web and there are diff. answers...) Can some1 plz help me?

Hope someone can help me on this one. I have an unknown substance, but i'm quite sure that its Fe(3+), and it is treated to 1.0cc of dilute hydrochloric acid and then 0.6cc of aqueous chlorine. When i carried out this in the lab, nothing happened, the colour of the solution remained the same. What is this testing for? ..any help appreciated.

hi im in grade 11 and im just confused with this one question ^^ a 200g bag of potato chips contains 4.8MJ of energy. How long would it take you working at your maximum body power to consume this energy? P=W/t (got that far)

I have just conducted a 3 way anove (all three IVs have 2 levels) and there are also 2 Dv's. However im now also suppose to run an apriori test on those results i have found to be significant. For my first DV i have found a significant interaction between 2 IVs and for my second Dv i have found a 3 way interaction but i have no idea how or which test im suppose to use???? I have read everything i have and all i seem to find is about post hoc tests but because of the strong literature it must be an a priori test. Can anyone help????????

Hi guys, i was wondering if you could give some help here is the question: The Electroscope 3.bring the charged rod near the scope then touch the ball with your finger, withdraw the rod and your finger. a) what happend ? Explain i said this: the 2 foils repelled because the rod is negative and your ginfer gets extra negative electrons and 2 negative charges repel. (teacher wrote: partly correct)

We have to do worksheets, and they're very poorly made. The questions and answers only have a vague connection with the material in the books. So... can you wonderful people help me out? 34. Clean up of contaminated soils is done by... a) washing it with detergent b) burning it c) injecting microorganisms into the soil to "eat" the organisms d) all of the above e) none of the above The first two sound ridiculous, and if it's none of those two it can't be D, so I'm leaning towards either E or C. Probably E since none of the other answers are E, but C sounds plausible enough. Not that I'd know since the book doesn't seem to answer this. 37. Which of the fol…