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  1. R

    Finding Ek with force, mass, and time.

    Homework Statement A 10kg box at rest is being pushed on a frictionless surface by a force of 10N. The force is in the same direction as the motion of the box. 10 seconds later, how much kinetic energy will this box have? Homework Equations 1. F=ma 2. Vf=Vi+at 3. Ek=0.5mv2 The Attempt at a...
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    Figuring out the amount of CO2 that goes into the atmosphere when cooking a roast

    I've changed the numbers a bit so things work out a little easier Homework Statement The combustion of propane in a BBQ follows the balanced chemical reaction: C3H8 + 5 O2 ---> 3 CO2 + 4 H2O As this reaction occurs, approximatley 3000J of heat is released. If a roast takes approx...
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    Faradays Law - Induced Current

    Homework Statement A loop of wire is situation between a wire (Wire 1) that is perpendicular to the loop and another wire (Wire 2) that is parallel to the loop (the diagram has the loop and Wire 2 in the plane of the page, Wire 1 is running "through" the page). Is a current induced, and in...
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    Having trouble plotting this set of data - please help.

    So: we did an experiment to see if sow bugs liked a dry or a moist environment. We put them in a choice chamber and let them choose between a dry environment and a humid environment. We also did a seperate control where we gave them the choice between two identical dry environments. My...
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    Archived Charge and Energy for Capacitors in Different Configurations

    Homework Statement How much energy must a 12V battery expend to fully charge a 0.15 uF and a 0.20 uF capacitor when they are (a) in parallel and (b) in series? How much charge flowed through the battery in each case? Homework Equations i: C(eq)=((1/C1)+(1/C2)+...+(1/Cn))^-1 and...
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    Why would leaves in a K+ solution have more open stoma than leaves in a Na+ solution?

    OK - that has help immensely. I realize now that sodium channels are highly selective and I did a quick read up on the topic. Thanks. So - last question. Have plants evolved to have more potassium ion channels than sodium channels? If this is the case, then we can make some conclusions.
  7. R

    Why would leaves in a K+ solution have more open stoma than leaves in a Na+ solution?

    Yes, I realize there is much literature on what potassium does, seeing as how that's what typically moves through the transport protein. There isn't lit though, on why sodium is less effective is opening stomata. Could it be that plants have simply evolved to use potassium, and therefore...
  8. R

    Why would leaves in a K+ solution have more open stoma than leaves in a Na+ solution?

    Homework Statement So we did an experiment where we put a leaf section in KCl and another leaf section in NaCl. There was a marked difference in the percent of stomata that opening between the two. We let the two sections sit in solution for 60 mins each. The leaves in KCl had almost...
  9. R

    Speed of an electron in an electric field - trying to find my error.

    That would do it. I end up getting 7.53x10^6 m/s. Seems high - thoughts before I submit?
  10. R

    Speed of an electron in an electric field - want to check answer before submitting.

    Homework Statement Two stationary positive point charges, charge 1 of magnitude 3.45 nC and charge 2 of magnitude 1.85 nC, are separated by a distance of 50.0 cm. An electron is released from rest at the point midway between the two charges, and it moves along the line connecting the two...
  11. R

    Electric field

    So.. F=Eq E=F/q - we know q but we need F. For it to hang suspended, there needs to be no net force acting on the bead. The electrostatic force is one of two forces acting on the bead; as well as being the F in our equation. So...this "other force" needs to be equal to the...
  12. R

    Speed of an electron in an electric field - trying to find my error.

    Homework Statement Two stationary positive point charges, charge 1 of magnitude 3.45 nC and charge 2 of magnitude 1.85 nC, are separated by a distance of 50.0 cm. An electron is released from rest at the point midway between the two charges, and it moves along the line connecting the two...
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    Stoichiometry Help?

    I know this is probably useless but, I thought I would give it some closure since some replies were filled with snide remarks and little was done to resolve the question at hand. First, I see nothing wrong with the equation, as far as I know, that's the combustion of sucrose and it's balanced...
  14. R

    How much energy does it take to cool and heat up water

    As Borek said - water has to gain or lose energy to heat and cool, respectively. The enthalpy change is always in relation to the system. Heating: system gains energy: enthalpy change is positive Cooling: system loses energy: enthalpy change is negative Yes, that is correct. Cooling an...
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    Do plants destory auxin intentionally?

    So - plants bending towards light. Light kills auxin. Shaded side grows faster so plant bends toward light. Was this an evolutionary mechanism developed by plants? Thinking of natural selection - were plants with auxin more successful since they could p/s more which meant higher rates of...
  16. R

    How far are we?

    Heh. Your thinking makes more sense...much more. I based that on a limited understanding of natural selection, it would seem.
  17. R

    Within ourselves, does blood have an expiry date?

    I would assume that blood, within us, is only good for so long but, I could be wrong. Also, if it does become "bad", where does it go? How do we get rid of "garbage blood"?
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    How far are we?

    Possible? I would think so. Chances? Slim-to-none. First thing, we don't even have a concrete theory as to why we age. I would argue that natural selection - removed from modern medicine and technology, favors longer life spans. So, clearly living longer is on the up. However, as far as...
  19. R

    Electric field from two point charges and then some

    Homework Statement A point charge, q1, has a charge of 3.4x10^-9 C. A second point charge, q2, is place 2.1x10^-6 m to the right of q1; it has a charge of -10.2x10^-9C. A) What is the magnitude of the field 8 mm to the left of the centre of the two charges? B) You could also treat...
  20. R

    Electric field produced by 2 point charges

    Took a stab at it. I was correct. Thanks regardless.
  21. R

    Electric field produced by 2 point charges

    Homework Statement A small object A, with a charge of -2.78x10^-10 C, creates an electric field. At a point P located 0.250 m directly north of A, the field has a value of 40.0 N/C directed to the south. If a second object B with the same charge as A is placed at 0.250 m south of A (so that...
  22. R

    Are larger seeds more sensitive to NaCl than relatively smaller seeds?

    So, we grew "large seeds" and "small seeds" in a certain concentration of NaCl. We also grew the same kinds of seeds in regular water. The control group data showed that the larger seeds had a longer radicle than than the smaller seeds. The NaCl group showed the same; larger seeds=relatively...
  23. R

    Do larger seeds need less water to germinate?

    Or, put another way, will larger seeds generally germinate more oftern than relatively smaller seeds, in drier conditions?
  24. R

    Why would smaller seeds be more sensitive to saline water than larger seeds?

    So, we were using ungerminated seeds for the experiment. The comparison to radicle length was made between the two types of seeds. The smaller seeds had longer radicles compared to the larger seeds; given equal exposure to an NaCl concentration.
  25. R

    Why would smaller seeds be more sensitive to saline water than larger seeds?

    So, we did an experiment where we exposed two different sizes of seeds to varying concentrations of salt water. The "small" seeds had, on average, shorter radicles than the larger seeds. So, it seems that smaller seeds are more sensitive to the saline solution. I'm just a little confused as...
  26. R

    Resources for biology extended essay

    Google: "Google Scholar" It'll come up with published articles for public use.
  27. R

    Effects of mutation isn't always visible how does one know that a mutation has occur?

    I assume you mean phenotypically? If so, it would be a silent point mutation. In this, a single nucleotide is replaced by another but, the sequence will still code for the same amino acid, and as such the protein will not change. Genotypically, it could be one of several types of mutations. It...
  28. R

    Several questions regarding an ideal gas.

    Homework Statement Making jam and then putting it into jars is called canning. The process involves putting the jam into the jars while it’s still quite hot; hot enough to kill germs. While canning some strawberry jam you notice that the lid pops in towards the jam when the temperature drops...
  29. R

    Using the Fundamental Theorm of Calculus II to evaluate indefinite integrals

    Thanks - I ended up using my calculator for the sake of this question and its: 1. 172.5 2. 11.75833 3. 0.000011977
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