Skip to content

Homework Help

For assistance with (but not answers to) homework problems.

Homework Help Rules

A simple reminder to all: this is the "Homework Help" forum, not the "Homework Answers" forum. We will not do your work for you, only point you in the right direction. Posts that do give the answers may be removed.

  1. Started by atotiace,

    This is my first post on this site. I had a question about saturated water properties. If you know the temperature of water and you are looking at a table of properties. What does it mean if your pressure is above the saturation pressure? Does that mean it is super heated vapor or incompressible liquid? I never could get a grasp on that.

    • 0

      Reputation Points

    • 0 replies
    • 700 views
  2. Started by bio_chem,

    I'm a little stuck on a problem that requires me to explain how I would use the process of serial dilution to create solutions of 0.05mM, 0.10mM, 0.25mM, 0.5mM, and 1.5mM from a stock solution of 10mM. Normally, I see problems where the ratio between the solutions is equal, so you would basically take, for ex. 1mL from the stock, and mix it with 9mL of water, and repeat this process for the following dilutions. In this case, however, the ratios between the solutions are not equal (0.10mM is twice that of 0.05mM, while 0.25mM is 2.5 that of 0.10mM). If the ratios aren't equal between the solutions to prepare, then how should one go about using serial dilution? Any help…

    • 0

      Reputation Points

    • 1 reply
    • 2.7k views
    • 1 follower
  3. Started by zzinfinity,

    I have this homework question. How many lines as a function of n (in O( )) form does the following program print? Write a recurrence and solve it. You may assume n is a power of 2. function f(n) if n>1: print_line('Still Going') f(n/2) f(n/2) The recurrence relation I came up with is 2T(n/2)+ O(1) so a=2, b=2 and d=0. So by my understanding of the master theorem the number of lines printed is O(n) But that doesn't feel correct to me. Since the size of the problem is being reduced by half each time, it seems the answer would be O(lg(n)). So my questions are, 1. Did I set up my recurence relation correctly. 2.…

    • 0

      Reputation Points

    • 0 replies
    • 948 views
  4. Hi! When crossing two separate species for example a 2n=12 and a 2n=28 how would I go about figuring out the diploid number in one of the progeny? Would it be 24 since 2n=12 can only pair with 12 of the 28 from 2n=28? And since there are 16 chromosomes from 2n=28 missing a pairing partner would the progeny be sterile?

    • 0

      Reputation Points

    • 0 replies
    • 840 views
  5. hi what is the difference between impact distance and horizontal distance? thanks

    • 0

      Reputation Points

    • 1 reply
    • 771 views
  6. Started by AlphaWZW,

    What is the argument of -i? On an Argand diagram, there is only 1 line... How you find the argument of -i without a real number?

    • 0

      Reputation Points

    • 2 replies
    • 3.8k views
  7. Started by jeyshree,

    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.

    • 0

      Reputation Points

    • 1 reply
    • 805 views
  8. Started by ALewo90,

    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 …

    • 0

      Reputation Points

    • 5 replies
    • 1.7k views
  9. Started by MasterCobra,

    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 …

    • 0

      Reputation Points

    • 0 replies
    • 1.2k views
  10. Started by violinboy12345,

    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!

    • 0

      Reputation Points

    • 1 reply
    • 953 views
  11. 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!

  12. Started by Master Ott,

    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

    • 0

      Reputation Points

    • 0 replies
    • 806 views
  13. Started by daniw87,

    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…

    • 0

      Reputation Points

    • 0 replies
    • 881 views
    • 1 follower
  14. Started by science10101,

    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.

    • 0

      Reputation Points

    • 2 replies
    • 1.6k views
    • 1 follower
  15. Started by coach94,

    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.

    • 0

      Reputation Points

    • 16 replies
    • 3.9k views
    • 1 follower
  16. Started by chamz,

    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

    • 0

      Reputation Points

    • 3 replies
    • 1.6k views
    • 1 follower
  17. Started by coach94,

    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?

    • 0

      Reputation Points

    • 15 replies
    • 1.9k views
  18. Started by Violagirl,

    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…

    • 0

      Reputation Points

    • 0 replies
    • 1.7k views
  19. Started by dwfan3,

    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…

    • 0

      Reputation Points

    • 1 reply
    • 5.7k views
  20. 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.

    • 0

      Reputation Points

    • 1 reply
    • 9.4k views
  21. Started by coach94,

    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).

    • 0

      Reputation Points

    • 2 replies
    • 3.3k views
    • 1 follower
  22. Started by NARUTO,

    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.

    • 0

      Reputation Points

    • 0 replies
    • 743 views
  23. 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

    • 0

      Reputation Points

    • 1 reply
    • 828 views
  24. 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

    • 0

      Reputation Points

    • 0 replies
    • 1.6k views
  25. Started by eLg,

    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?

    • 0

      Reputation Points

    • 23 replies
    • 9.5k views

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.