Homework Help

Hai, When a liquid passes through an area with smaller cross section why does pressure get reduced?What i understood is that as the contact area has decreased the pressure should have increased.What is wrong in my perspective?Please correct me.Explain me practically.Dont mention the derivations please.Thanks for your reply in advance.Have a great day.

Hi there I need some help with a PCR experiment I had to do for an assignment and I'm not sure if I completely understand whats happening in the agarose gel photo. I've added the gel photo and also the molecular weight marker used. lanes (from left to right) 1=negative control, 2=chicken DNA, 3=cauliflower DNA, 4= Molecular weight marker this experiment was to see if using the same primers produced from cauliflower beta-actin, and by adding them to chicken DNA if they would amplify the same sequence. I would expect it not to amplify the same, and the gel photo shows the brightest chicken fragment higher than the cauliflower. but then there is also a fragment …

Hello everyone, I have homework to do about the cytoskeleton and its use in cell motility and I wanted to confirm some of my answers with you guys. Here's the problem: We have the result of a simple scratch test (cells come into confluence in a Petri dish, we make a scratch and study the cells' ability to close the gap) There is a control test, where we see the normal cell motility and 2 study tests: Group A: there is an evident acceleration of cell motility compared to the control test Group B: there is no cell motility And I must associate a different bunch of conditions to either group A or group B, as the expected results …

Hello, I am a high school freshman, and my science teacher is making the class participate in a science fair. I've chosen my topic to be the effect of external, ambient sounds on the rate of cricket chirps, so can anyone give me a few links to previous researches that relate to this? Also, I would appreciate if you can suggest some small changes to my topic, in case you notice something vague, etc. Thanks!

Please can you help me with this? I think that I understand the basics of the Heisenberg Uncertainty Principle, however don't know how the fluctuations that cause matter to appear, appear themselves. I do understand that users who comment on this thread mustn't give me the answer, however I would appreciate it if you could direct me towards the correct websites. Thanks in advance; it's for a debate on Monday, so replying soon would be great!

I'm looking for an equation to find pressure as a function of time in a 10 cubic inch tank being filled from a 120 psi source through a valve with flow coeficient Cv=0.28, and a 2.5mm orifice size. I think that ultimately the answer comes from Navier Stokes equation, but I'm hoping someone can help me find a simplification that will work for my problem. Suggestions appreciated! P.S. I need to account for compressibility, and viscous flow

Hi everyone, I am currently trying to identify some unknown bacteria for a lab project. We've been given a case study where we have to identify potential pathogens in a sample of dam water. I have two species, which I am finding really difficult to identify!! Can anyone help or guide me in a good direction please? DAM SAMPLE 1: Gram negative singular, coccobacilli red pigmented colonies on all nutrient agar γ haemolytic non-lactose fermenting non-halotolerant catalase + oxidase - + glucose, mannitol, xylose, ONPG, Indole, Urease, VP, Citrate, TDA. DAM SAMPLE 2: Gram negative γ haemolytic lactose fermenting non-halotolerant cat…

Use the Henderson-Hasslebalch equation to calculate the volume of 0.20M NaOH required to adjust the pH of the 0.10M acetic acid solution to the pKa value of acetic acid. Note: you will first need to calculate the number of moles of NaOH and then use the concentration of the NaOH to determine the corresponding value. I do not understand where to start since to find number of moles of NaOH you need the volume but the volume was not given.

I can't use K-Map's i only can use boolean algebra to solve these problems This is an example of one of the many things i need to simplify using boolean algebra D'C'B'A+D'C'BA'+D'C'BA+D'CBA'+D'CBA+DC'B'A'+DC'BA Any kind of help is appreciated, I honestly dont even know where to start.

what is the work produced by any gas during totally unrestricted process 1 - 0 2 - equal to the heat added 3 - mR(T2-T1)/(n-1) 4 - mRln(T2/T1) (i know its not 3 , 4 cuz the problem says any gas) the following properties will remain const after a cyclic process 1 - p,v,T, U only 2 - none of the properties 3 - v,T,and U 4 - all of the properties is it 1 or 4 pls help exam is on monday

I have this diagram I am trying to find the boolean equation for this. I know (d+c)(ba) I dont know how to write the equation to include the box X anyone give me a hand?

The question: Assayed for LDH activity were 5 uL of a sample that was diluted 6 to 1. The activity in the reaction vessel, which has a volume of 1 mL, is 0.10 U. What is the A/min (absorbancy/minute) observed? What is the relative activity of the original sample? Here are the formulas: U=(ΔA/Δmin)/((6220 M^-1cm^-1)(1cm))X 10^6 micrometer/M X10^-3 L Relative Activity: U/mL= U/(volume of fraction assayed) X dilution used, if any. This is how I thought about solving the problem: A/min = 6220 M^01 cm^-1 (cm) x 10^6 uM/M x 0.001 L/ .10 U = 6.22 x 10^7 (????) For the relative activity of the original sample, since it has to be in units of U/mL of fraction, I was thi…

my science teacher has set a practice ISA as homework however my teacher never really ran through it in class clearly so I seem to be stuck on the first question. I know it's just a practice one but the real test is worth 25% of my end of year GCSE grade in science and I would really like to do well. I have asked some of my peers for help but they're all in the same situation as me (also could any of you please clarify what a 'preliminary investigation' is in science and what it's for because I'm not entirely sure as to what it is, my teacher never told anyone about it...) If any of you think you can help I'd really appreciate if you could answer as soon as poss…

I'm stuck on these two problems: A) IF you make a 50 mL of a 0.1 M Tris solution (in acid form), what will be the pH? B) If you add 2 mL of 1 M NaOH to the above solution, what will be the pH? I'm not sure how to go about solving this. I know HH equation is typically used when is a concentration is given but how do you account then for the volume given? Any help is great.

Ive been stuck on this problem for a bit, I'm not exactly sure what equation to use to solve it so any help pointing me in the right direction is appreciated! You are traveling on an airplane. The velocity of the plane with respect to the air is 120 m/s due east. The velocity of the air with respect to the ground is 44 m/s at an angle of 30° west of due north. what ive found : planes speed relative to the ground is 105.15 m/s question i can't figure out : 1) What is the heading of the plane with respect to the ground? (Let 0° represent due north, 90° represents due east).

Hi, I'm trying to solve a PDE: ux + u2 uy = x using the method of characteristics using the following condition u(0,y) = ay where a is constant. So far, I obtained this system of ODE: dx/dt = 1 (1) dy/dt = u2 (2) du/dt = x (3) (1) => x = t (3) => u= 1/2 x2 + a s (2) => dy/dt = (1/2 x2 + a s)2 Now my problem is that when trying to solve (2) (which I manage to do, y= 1/5 t5 + 1/3 t3 as + (as)2 t + s), I get a second order equation is s, when I tried to solved I found a delta which I don't know its sign and therefore I wasn't able to express s as a function of x and y. Any help is appreciated. Many thanks.

Hi, I am trying to work on this problem, but I donèt understand it. this is the problem: A compound of molar mass 229 contains only carbon, hydrogen,iodine, and sulfur, Analysis shows that a sample of thecompound contains 6 times as much carbon as hydrogen. bymass. Calculate the molecular formula of the compound. my solution is attached..I am stuck.. . Help please

Hi, I am trying to work on this problem, but I don't understand it. this is the problem: A compound of molar mass 229 contains only carbon, hydrogen,iodine, and sulfur, Analysis shows that a sample of thecompound contains 6 times as much carbon as hydrogen. bymass. Calculate the molecular formula of the compound. my solution is attached..I am stuck.. . Help please

Can someone tell me how to approach this problem. I don't need to see any solution. I just want to know the steps in solving this kind of problem. A 6.01 g sample of copper is contaminated with an additional 0.64g of zinc. Suppose an atomic mass measurement was performed on this sample. Do I have to create a balanced equation, and convert the values for moles?

Help please. Which compounds would be formed in the reaction of ethene with aqueous bromine in the presence of sodium chloride? 1 CH2ClCH2Cl 2 CH2BrCH2Cl 3 CH2BrCH2Br I know that electrophilic addition occurs when ethene reacts with bromine. But what happens with NaCl? What kind of reaction is it? Can it be free radical substitution? Is Cl from NaCl a free radical? Because it's not Cl2 where UV light is required to break the bonds to create free radicals.

I need some help with converting from roman numerals to ASCII code. I would just like a better understanding of how to do it My teacher gave us the following table and we have to get the rest of the code ( 0-6, 10-12) and i honestly have no clue where to go when it comes to the ASCII code I cant really find any good resources online to figure it out.

Hi everyone I have a genetics problem that I'm struggling with, Here is the problem: Can you devise a simple formula for the calculation of the number of progeny genotypes in dihybrid, trihybrid, and so forth crosses? Repeat for phenotypes. I'm struggling to understand this problem. If somebody can give me a little "push" and help get me started, I would greatly appreciate that. Thanks.

Hello, Just started my metabolism course and it's been about a year since my last biochemistry course so I've got to refresh myself on some of the basics. In a section of my textbook that was talking about the regulation of metabolic pathways, it said: "The first committed step [of a metabolic pathway], being irreversible, functions too slowly to permit its substrates and products to equilibrate. (if the reaction were at equilibrium, it would not be irreversible)" I'm a little confused, wouldn't an irreversible reaction be faster than a reversible one since the product is not continually being converted back to the initial substrate? Irreversible reactions are h…

Question: How many grams of sodium oxide are produced when 73.2g of sodium react completely with oxygen gas? Just want to confirm if my procedure/answer is correct. 4 Na + O2 ---> 2 Na2O ----- Balanced Equation So I would assume all I have to do is 1) get the moles of Na 2) divide my 2 to get the moles of Na2O 3) multiply by the molar mass of Na2O to get the grams of Na2O. Solution: 73g ÷ 23g/mol (molar mass Na) = 3.2 moles 3.2 moles ÷ 2 = 1.6 moles of Na2O 1.6 moles × 62 g/mol (molar mass of Na2O) = 98.7 Did I do my computations correctly?

What is the volume of 10kg of a liquid which has a relative density of 10.2? What is the volume of a gas which has a mass of 24lb and a relative density of 0.86? Remember first one is in metric And can you please show your work! Thanks