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    Diverging lenses + mirrors

    I noticed that for converging devices the size and orientation of the image formed depends on whether the object is located inside or outside the focal point and center of curvature. I also read that no matter where the object is with respect to a diverging lense the image formed will always be...
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    Trajectory of charged particle moving in a magnetic field

    Ah right that explains it. Thanks a lot.
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    Trajectory of charged particle moving in a magnetic field

    Damn I meant to say pink lines in the diagram not green lines. What I was really asking is if the pink lines are the magnetic field lines. I see that the green circular lines are the trajectory of the particle but I'm wondering if the particles initial velocity upon entering the magnetic field...
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    Trajectory of charged particle moving in a magnetic field

    In this video here are those pink green the magnetic field lines? If so where does the proton come from? If I'm not mistaken a charged particle in motion will only be influenced by the magnetic field if its not moving parallel to the magnetic field lines but in this video the proton appears to...
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    Rectifying an conventional error

    Rectifying an "conventional error" In textbooks I always see "by convention it is said to flow from positive to negative but in reality its from negative to positive" and this is why I always end up explaining that when I get asked a question about how current works or how batteries work on a...
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    Calculating pKa when pH is known

    I started this thread a while ago but never figured it out in the end can someone tell me if my idea of this is correct or not. Lets say I add 2 moles of a weak acid acetic acid to a liter of water (at STP). If I'm not mistaken the acetic acid will dissociate slightly depending on its...
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    The strength of strong acids

    Sulphuric acid is a diprotic acid that dissociates completely when dissolved in water. How does a monoprotic acid like trifluoromethanesulfonic acid produce a greater pH change than H2SO4?
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    Calculating pKa when pH is known

    I submitted that assignment already I'm not asking for help with that question I'm trying to learn the concept. If I add 15 tons of pure NaOH to a 10 litre bucket of 0.0005M CH3COOH solution theres no way the amount of acetate ions present is going to equal the god knows how many moles of NaOH...
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    Calculating pKa when pH is known

    All I know is that acetic acid is a weak acid and it doesn't dissociate fully into acetate and H+ ions when dissolved. I know KOH is a strong acid. All the charged species are K+ and H+ cations as well as OH- and CH3COO- anions. I know exactly how many K+ ions are present and ignoring the...
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    Motivation for learning maths

    Thanks a lot! What you said "being able to come up with methods to link the variables in an unknown problem together" got me thinking. The only 3 variables I've thought about are acceleration, velocity and displacement but there are probably plenty of these variables within variables that I'll...
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    Calculating pKa when pH is known

    Heres my calculation The real pKa of acetic acid is around 4.7 so I wasn't too far off. I still don't know why the acetate ions are equal to the KOH though. If I react some acetic acid with KOH is it only the dissociated acetate ions that are involved in the reaction?
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    Motivation for learning maths

    I usually have no shortage of motivation because I like to think about all the practical applications that I could use this theory for in my future endeavours and also how the theory I'm learning expands on and fills in the gaps of what I already know. In maths I can't automatically think of...
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    Calculating pKa when pH is known

    Heres a question involving what I'm talking about When 5mls of 0.05M CH3COOH is allowed to react with 1.5mls of 0.05M KOH. The pH is found to be 4.43. Using the Henderson-Hasselback equation calculate the pKa. My teacher told me that you can find the amount of dissociated ions of the...
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    Van der Waals Forces

    Thanks.
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    Calibration Curves

    I looked this up but couldn't find sufficient information on it. What I know is that calibration curves are used to find the concentration of an unknown compound by graphing a series of measurements of a property like light absorbance from standard solutions of that compound. What I don't get is...
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    Van der Waals Forces

    Is Van Der Waals forces just a name for all intermolecular forces that exist between molecules or does it only refer to certain types of intermolecular forces?
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    Touching both terminals of a battery

    Thanks. I didn't know skin had such high resistance.
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    Touching both terminals of a battery

    Ah right that explains it I bought a "household meter" so its probably build for AC.
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    Touching both terminals of a battery

    Sorry if this is the wrong forum. When I just touch any part of the metal of both terminals on a 9V battery with a multimeters probes the meter displays the voltage (although it said 20V not 9V for some reason). What I'm wondering is why people don't get electric shocks from touching both...
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    Momentum vs. Kinetic energy

    I can see from the formulae that a bullet will have greater KE than the gun even though the mometum of the kickback is equal to that of the bullet. I also know that a bullet will do a lot more damage to a wall than the backfire of the gun. Whats behind this? Is it simply the concentration of...
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    Relative velocity of perpendicular vectors

    It didn't make any sense what I was describing there did it. What I was trying to describe was something more like the relative velocity of the river with respect to someone jumping over the river but the resultant vector in that case would be the opposite direction. What I'm really wondering is...
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    Conservation of momentum with initial velocity of 0

    I'm having a bit of trouble understanding the concepts of momentum conservation. Lets say I'm standing on a frictionless surface and I throw a 3kg brick horizontally with a velocity of 4m/s. In this scenario I can see that I'm going to be repelled backwards at a velocity of 12/my mass in kg but...
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    Learning In Between Semesters

    I recommend studying what you feel like studying at the time. The more interested you are in what your learning the quicker you'll absorb it. In that space of time you could easily cover the whole second year calculus material as well as get a huge head start in any physics your course will cover.
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    Courses Elementary physics courses - 95% about knowing formulae?

    I was stoned when I started this thread. I wasn't even taking into consideration the amount of effort I've put in so far to understand every concept we cover in the class. When I don't understand a concept I spend hours visualizing it and approaching it from different angles until I fully...
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    Relative velocity of perpendicular vectors

    Using this diagram as an example http://img25.imageshack.us/img25/231/diagramig.jpg [Broken] would I be right in assuming that the relative velocity of the boat with respect to the velocity of the current is the speed at which its moving away from say a stone floating down the river? In other...
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    Simple pulley systems

    I'm fairly fascinated by the idea of mechanical advantage using pulley systems. Using this pulley system http://www.swe.org/iac/images/plly_071.jpg [Broken] as an example I read that this provides a mechanical advantage of 4. If I'm only putting say 20N force in and the block weights 80N where...
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    Cho sha cao

    Haha its easy to remember I suppose. Another one I came up with for biology is PMAT - Prophase, metaphase, anaphase, telophase. Interphase and prometaphase I remember naturally.
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    Are t-cell receptors antibodies?

    I read that t-cells have receptors on their surface which bind to antigens. Are these receptors antibodies or are antibodies molecules which float around freely and mark antigens that they happen to bind to so that t-cells can kill them?
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    Centrosome migration

    Do the centrosomes start moving toward opposite poles of the cell in prophase or prometaphase in mitosis? Can anyone tell me if my explanation of mitosis is accurate. Interphase - DNA, centrosomes and organelles are replicated. Prophase - Chromosomes condense and nuclear envelope...
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    Pyruvate decarboxylation

    Thanks.
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