Homework Help

A question from my Body Systems Physiology heart practical... True or False: 'Action potentials in contractile ventricular muscle cells exhibit a different electronic profile, relative to cells of the SA node, due to a stable resting membrane potential, and the opening of voltage gated Ca2+ gates and delayed opening of K+ gates, during the AP.' Any help would be greatly appreciated!

I posted about my biology paper--I think it was yesterday-- and now I need help again. Every website and book I consult has different numbers on rainforest percentage. Some say less than 2 percent, some say 3 percent, some say 6, and some even say 10 percent of the earth is covered in rainforest. I do not know which one to put in my paper. Maybe you could help me with this. It would be apreciated. Thank you. EDIT: Crap, I should have put this in the homework section.

so im writing up a pre-lab for class and we have to find the mmol of various compound and i always get stuck when the measurement of compounds are in mL i have NaOCl (sodium hypochlorite) the FW is 77.44 g/mol and density is 1.083 g/mL..... we are using 18 mL of it. can someone help me out???? P.S. the experiment is the oxidation of borneol to camphor

Hello lovely people who help us out! Stuck on a couple of bits of my tissues assignment on structure and function of cells/ tissues- if anyone could point me in the right direction I'd really appreciate it! 2 reasons for muscle cells being long: I've put so they can contract/expand but reason 2- is it simply so they can run the long distances that they need to? (i.e. length of femur or similar) 2 adaptations of compact hard bone (histological structure) with relation to function- 1: bone is dense, so provides strong protection for e.g. brain, but I don't get what number 2 is- something to do with the network of haversian canals? But what is the function of tha…

Another physiology question I am not sure about... True or False: 'In smooth muscle, the amount of actin and myosin is the same as in skeletal muscle but smooth muscle lacks troponin.' I know smooth muscle has no troponin, but not sure whether is has more/less actin and myosin than skeletal muscle? At a guess, I would say skeletal is likely to have more actin and myosin, but not sure. Help will be appreciated

I'm writing a paper for biology class and we are allowed to choose our topics. I chose biodiversity and why it's important. I have written the intro and some of the body, but I just want you to read the intro and tell me if anything needs to be improved, removed, or if there are any grammar mistakes. Here it is: "What is biological diversity (or biodiversity)? 'Biodiversity' is a collective term meaning 'all life on earth'. The Convention of Biological Diversity defines biodiversity as: 'The variability among living organisms from all sources, including inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are ap…

Hello! I'm working on duplicating the optics experiment outlined here: http://www.lhup.edu/~dsimanek/scenario/labman3/telecen.htm The gist is using a lens with a small aperture at the focal point to filter out light rays that are not perpendicular to the lens, creating an image without perspective distortion. I'm trying this with a fresnel lens, it's about 8"x10", and the focal distance is [very] roughly 9". I can get it to the point of what is basically a camera obscura (pictured below), but I'm finding the setup as I understand it does not yield the results described in the experiment. When I place an aperture in the focal plane and move the screen materia…

I am having serious trouble with this question and I'm hoping to get some assistance with it. The question goes as follows: Suppose a lens with a focal length of 10.0cm produces an inverted image half the size of a 4.0cm object. How far apart are the object and image? Show all your work. Any help is appreciated.

The distribution of men's heights has a mean of 68in, standard deviation of 2.5in. If the heights of brothers have a correlation of 0.5, what is the mean and variance of the difference in heights between pairs of brothers? I know that r=Cov(x,y)/(sqrt(V(x)V(y)) so 0.5=Cov(x,y)/(sqrt(2.52)(V(y)) but then I'm stuck trying to solve the Cov since they arent independent, E(xy) does not equal E(x)E(y) I have the solution, can't see how to get there. The solution: mean=0, variance=6.25

Hi everyone, I'm not sure if this is the forum where I should post this in lol. Anyway, I'm working on a research, and I need participants to participate on this survey: http://www.mywebtaste.com/ In the link you'll go through 24 pages with different websites screen shots. I would like to ask you to click on those websites that you find most appealing at first sight. This test is a part of an experiment about culture and its related to the web taste. It would take you only 3 or 4 minutes. Thanks So if you could participate and share it to your friends, I'd appreciate it for you guys. Also, I want to ask you guys. Do you know a good way to have Chinese…

Ok, So I've completed the question #8 from textbook. What I'm confused about is question #9. Here is the question 8. #8. For each substance below, identify it as ionic or molecular. Explain how you came to your conclusion. a) Compound 1: melting point: 48C, low solubility in water, flammable, mild odour, colourless solid easily crushed My answer: molecular - because of low melting point b) Compound 2: melting point: 800C, highly soluble, solution is highly conductive, hard, white crystals My answer: ionic - because of high melting point + tight crystal structure c) Compound 3: melting point: 185C, decomposes at 190C, highly soluble, sol…

Hey, so im doing a biology EEI on finding the lowest effective concentartion of alcohol ( both isopropyl and ethanol individually) against certain bacteria. I have chosen Bacillus subtillis (gram positve) and Rhodospirrillum rubrum (gram negative). I was just wondering if anyone knew any sites on concentrations needed? Ive come across a few, some saying about 50% others saying roughly 70%. Bear in mind i am only in yr. 12, so it cant be too technichal or i will have no chance of understanding. Also i came across a lot of wiki stuff, but ive found its not too reliable so im trying my best to steer clear. Any suggestions? Please and Thankyou.

hello everyone I just have attend my first class in system analysis design, and the professor asked me to do an assignment in ( JAD ) Joint application design, and I am suffering the lack of information as well as how to write a good abstract, with past practice and present. and I have come up with this abstract: Joint application design (JAD) is a technique forpromoting cooperation, understanding, and teamwork among buyers, users anddevelopers, it provides a process that facilities creating a shared vision whatthe system should be. Using that process, the developers help the usersformulate problems and explore solution, and the users gain a feeling of i…

My homework question is: a) Find the equations of both lines through the point (2, -3) that are tangent to the parabola y=x^2+x b) Show that there is no line through the point (2, 7) that is tangent to the parabola. (Is it because the point (2, 7) is "inside" the parabola, and any line radiating through that point would intersect through the parabola?)

i could have managed it all if i had an extra arm this made everyone silent. why do you think silence fell? also state davids society religious fears the rules they have made to deal with them support your answers from the text

Ohm's Law - Resistance? Below are the results of an experiment my group did at school while I was away sick. The experiment was to determine the resistance of an unknown resistor. The Resistor's actual resistance was 2.2 ohms, but the results (as you can see) are all over the place. The circuit included a voltmeter, ammeter and rheostat (which was adjusted with each trial) I have been reading and reading about Ohm's law, circuits and percentage errors, but I have only managed to confuse myself more. Basically, I need to explain the results and if the percentage errors are acceptable, but I am having trouble understanding all of this. 1. Can someone please ex…

It is true that inter-molecular forces within carbon compounds is small.And that intra-molecular forces within these covalently bonded compounds is much stronger. Why does this happens so? Give reasons in each case

So, I'm trying to draw a diagram for ionic bond, the question asks me to choose two atoms that could participate, and draw the valence shell I chose Mg and S. So, Mg has 12 protons and 12 electrons, and 2 valence electrons. S has 16 protons, 16 electrons and 6 valence electrons. In the diagram, I drew two atoms with 3 shells, and I will draw an arrow pointing the electron transferring to S shell from Mg's outer shell. How does that sound? Only one electron is transferred to S shell, is this correct? Or two? Because in Mg's outer shell there are 2 valence electrons... Thanks guys.

Stars appear to twinkle whereas, planets do not. Why ? I am a bit confused about it by reading from books. Can somebody explain it clearly ?

If Beau is using his driver, wherein the club head is 180 cm further away from the axis of rotation than his hands, and his hands are 22" away from his shoulders (axis of rotation), how much greater is the average linear speed (VT=wr) of the club head than that of Beau's hands? The arc length for Beau's hands is .9652m. The golf club is moving at 43 m/s.

If beau is using his driver, wherein the club head is 180 cm further away from the axis of rotation than his hands, and his hands are 55.88 cm away from his shoulders (axis of rotation), how much greater is the average linear speed (vT=wr) of the club head than that of beau's hands? The arc length for beau's hands is .9652. The golf club is moving at 43 m/s. Answer should be in radians/sec.

1.) Let X and Y be sets and f:X→Y a function. Also let A с X and B с Y. (a) A с f-1(f(A)) with equality when f is injective. (b) f(f-1(B)) с B with equality when f is surjective. 2,) Let f:X→Y and g:Y→Z be functions. (a) If g ◦ f is injective, then f is injective. (b) If g ◦ f is surjective, then g is surjective. 3.) (a) Let R+ с R be the subspace of positive reals. Show that R is homeomorphic to R+ . (b) Show that (a,b) is homeomorphic to (0,1) . © Show that [a,b] is homeomorphic to [0,1] . 4.) Let X be a space. (a) If X is Hausdorff, then every convergent sequence has a unique limit. …

I cant find any images of an atomic structure and molecules or lattice structures for the following: Tugsten Polyethelene Silicon Carbide Quartz Crystal Glass Fibre Reinforced Plastic Shape Memory Polymer If you have any links to where I could find a suitable image for any of these please tell me. Thank you. PS. sorry I am not very good with chemistry I am a mechanical engineering student and am studying materials so thats why I need to know. Done some research more and found these, can you correct me if I am wrong please, I am not very good at chemistry. Tungsten Bohr Diagram: http://www.chemicalelements.com/bohr/b0074.gif Lattice Structure: htt…

Does fibre glass have a crystal structure or is it amorphous? (Does it matter what type of polymer is being used for the structure? I am using epoxy) Do shape memory polymers have a atomic structure and a crystal structure?

Hey guys just need a little assistance with some genetics homework. I am given a gene map and I am told that an inversion occurs between 3 of the 7 of the genes. It asks for the recombinant percentages which is simply just adding up the numbers between the genes. I just do not quite understand how to calculate the recombinant percentages when an inversion takes place. I attempted the problem and i just halved any number that was inside the inversion because i know that when an inversion takes place 2 chromosomes come out normal and two are affected by the inversion. I doubt this is right but any assistance would be great. If you need more information from the problem just…