Homework Help

Another question. Can a mixture have a different melting point from its constituent elements? thanks in advance

O.K. before we start I am in pre algabra/geometry. A round tablecloth hangs 1.5 feet over the edge of a round table with a diameter if 4.5' what is the area of a table cloth. I got 7.5' is this corect?

Calculate the pH of the solution which results from the mixing of 100.0 mL of 0.050 NaOH solution with an equal volume of 0.10 M HCl solution. Seems straight forward to me. Strong acid and a strong base, so they'll react completely. You end up with .05M HCl, which is the molarity of H+, so you can just use -log(.05) to get the pH. I get 1.3. But this is apparently incorrect, the answer given is 1.6. Can someone tell me where I went wrong?

The problem is attached to this thread. It's the bottom problem with the chart and 4 parts to it. It is labeled 2001: AB-2; BC-2 because it was a previous AP calculus problem. If you cant tell me the answer please tell me how to do it. thank you!!!! scan.pdf

Hey all, this is just small problem on dirac notation, just want to make sure that i have some idea of what i'm doing (we only just started this stuff this week! ) heres the question: and heres my answers: -Sarah

My friends and I are doing a project on digestions and it would help if we could find out how to test for enzymes. Thanks:-)

I have been given a question: Determine the enthalpy of reaction in kJ for the hydrogenation of acetylene to form ethane : C2H2 (g) + 2H2(g) --> C2H6(g) From the following data: 2C2H2 + 5O2 --> 4CO2 + 2H2O H = -2600 KJ 2C2H6 + 7O2 --> 4CO2 + 6H2O H = -3120 KJ H2 + 1/2O2 --> H2O H = -286 KJ So far i know H(h2o) = -286 kJ But i've swapped around reaction 1 (the first one where H = -2600) and added together the first and second reactions. Now i have: 2C2H6 + 2O2 ==> 2C2H2 + 4H2O H = -520 KJ But i dont know where to go from here, because i'm left with two unknowns, the 2c2h6 and 2c2h2. Any help app…

http://staff.fcps.net/kcrosby/march_20.htm[/url] 1. Describe the process that formed this land formation? 2. What is the name of this land formation? This picture was taken as I was traveling to Richmond, KY from Corbin, KY

Hi everybody, I've got a physics essay[or thesis] on Quantum theory and since there will be a lot of equations in my work, I am considering whether I should use Latex to do it. I've never used this program before though, so I was wondering whether; I should just use Microsoft word and the Microsoft equation interface on it, or download Latex and start learning how to use it? I have a timeframe of a 2 week holiday to do this work in, while revising for my A level exams, so I was wondering what you think would be my best option? thanx in advance:-) .

Hey all, i am a little confused with this problem.. well i have only tried part (a) so far, so that is what my current question is concerning. my problem is that when i work out c_n i get that it is some multiple of sin(n*pi) which is obviously zero for all n. in which case i cant work out Psi(x,t)?! i have put the integrals into maple and everything but it gives me the same thing... 0 any ideas anyone? -sarah

I need to express blood pressure in terms of kPa. The conversion is 1kPa - 7.5mmHg, or .133 kPa - 1mmHg, but how would this be expressed? Just kPa subsituting mmHg, ie kPa/kPa?

I have a basic understanding of the polar coordinate system. I have some questions that would help me with my hw though. (1) how do I take an equation like 3cos(5 theta) and figure out how big an interval is for one loop. I know that there are 5 loops, i just don't know how to get the interval. (2)i know that when integrating to get area im going to take .5( integral from angle a to angle b of r^2 dtheta) i also know that if im finding the area between two curves i take the difference of r1^2 and r2^2 depending on whic yields a greater value, would i break the intervals up for when one function was greater then the other. any help is appreciated

why is the earth held in orbit around the sun? this may seem like a fairly simple question but ive tried 'googling' it and nothing, any help much apprieciated! cheers

I have to write a hard sci-fi short story for my Science in Science Fiction class and I was wondering if you guys could help me form some ideas. So far, I've had one idea: This scientist re-creates Miller's experiment, and accidently creates a new kingdom of species. Fast foward several million years... the new kingdom has produced a sentinent species and we have finally learned to live coopertively with them. Somehow, a member of this species (a historian, perhaps) uncovers the truth about how his species was created and is faced with a moral dillema... Should he tell the truth to the public (and risk threatening the very fabric of the current social structure), or …

Is anyone around hear who helps me? I need an article which is writen in Wourld's Poultry Science Journal 1996. Vol.52 page:309 I send mail to its author but he(Kidd M.T.) didn't answer me. Could anyone send me its PDF/photo. thanks very much:-)

Which of the following properties of a real gas is related to the 'b' coefficient in the van der Waals' equation? (P + n2a/V2)(V - nb) = nRT a) There are attractive forces between atoms or molecules of a real gas b) The rate of effusion of a gas is inversely proportional to the square root of the molecular weight of the gas c) Real gases consist of molecules or atoms which have volume d) The average speed of the molecules of a real gas increases with temperature e) None of the above Do you think the answer is c? Thanks

Hi, This is my first time posting so... hi Anyway, I have a question (which you may have guessed). I am writing a book/story which is about life on another planet and i am trying to keep it as scientifically accurate as possible. One thing which i need to know is; Is there any gas which is combustible in an atmosphere with no oxygen? Or even any substance? I'm pretty sure you will all say that all combustion is, is the rather hot, oxidising reaction which we see as a flame. My question is really asking however, if there was an atmosphere with no conventional earthly fire, could something at least resemble it or would i have to create something? I have to stay awa…

Hey guys, Doing a project on star formation and fusion. We did mass defects in class today, but we were using [math]{\Delta}E={\Delta}mc^2[/math]. Seeing as the mass is the rest mass of an object, can this be applied to protons when they are both at rest and in the nucleus? Thanks, Dan

Hi all, This isn't a homework problem as such, but it's a Lab question instead. First off, is it possible, using a solenoid with current passing through it, to levitate a second magnet? If so, how do you calculate the force of magnetic repulsion between two magnets? EDIT: OK, I found out it IS possible to do what I wanted. Now, I would appreciate it if somebody could tell me how to determine the force of attraction/repulsion between the magnet and the solenoid? Thanks in advance, LazerFazer

Yo, i am a 15-year-old student. One day I saw this in my assignment. A car of mass 1500 kg accelerates from rest at 5.00 m/s2 for 5.00 s on a straight road. Find teh minimum power needed for the engine to achieve this task. The answer they gave was Power = work done/time = 1/2 mv2 / t =1/2 m(u+at)2 / t =1/2(1500)(0+5x5)^2 / 5 =93750 =93.8W But my answer was Since m=1500 kg u=0 a=5.00 m/s2 t=5.00s F=ma=1500x 5.00 = 7500N v=u +at =5.00 x 5 =25m/s P=Fv ==> 7500x25 = 187500 = 187.5 kW Not only the answer is wrong, 187500 is twice as 93750. What happened? Please enlighten…

hey guys im having trouble working out this question. be great if ya can help. The position of a golfball is given by r = ((3t^2)i^ + (2t^2-1/6gt^3)J^)m. Calculate its velocity and its acceleration at time t = 1s (assume that g = 10ms^-2 i^ = i hat J^ = j hat

Today my teacher told us things about naming the acids but I get confused. 'Acid - an electrolyte which ionizes in water to give H+ (aq) as the only cation' quote from my notes. What does ionizes mean in here ? So it is an electrolyte? what's that? Can you explain to me , please. cheers

Hey all, i can do part (a) (or at least i think i can, i get: 9.4eV but for part (b), i can't find a formula to use. any ideas guys/gals? and for part © i caluclated that you would need to give ~28eV worth of energy to the an elecron to excite it to the first excited state. i am unsure whether this is said to be 'easy'.... do you think 'easy' involves cmplicated equipment or me poking it with my finger? sorry bout the 1000 questions Sarah

Hi Not sure if anyone can help me here. I'm doing a 3D project based on physics and dynamics. I wanted to know if anyone on here has, or could take, some photos of a double-pan beam balance. It could be a harvard trip balance, or an old one. From pictures on the internet, I am unable to see the underside of the pans and how they connect. I am setting this up in 3D and need to see all the components so I can model them, texture them, and then rig them and use rigid body dynamics so the balance will react similar to how it does in real life. Here is a link to a low quality image I found if you are not sure what model I mean. http://www.morrisonlabs.com/images/b…

Hi, Could you tell me what is meant by 'as respiratory substrate to release energy for metabolism' in the function part of Carbohydrates? And what is hydrolysis? Couldn't figure it out. thanks