Recent content by ice87

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    Shear Stress due to Laminar flow

    Homework Statement Oil of Density 888kg/m^3 and viscosity 0.8Pa*s is flowing in a horizontal pipe of diameter 0.15m. The local flow velocity at the centerline is 10m/s. find the shear stress exerted by the oil on the wall of the pipe. Homework Equations tau = -eta*(dv/dy) The...
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    Solving Hess's Law Problem for ΔH of Formation of Hematite

    roughly speaking I integrated the C_p function of Fe2O3 - hematite from 298 to 1200. I really integrated it three times, because hematite has 3 states in this temperature range, and the C_p function for each state is different.
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    Solving Hess's Law Problem for ΔH of Formation of Hematite

    So I'm taking Thermodynamics I in university. I'm just doing the homework now, and there is something that i don't really understand. To get the Enthalpy of formation for hematite (Fe2O3) at 1200K, I first integrated the constant pressure heat capacity function over the temperature range from...
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    Can Electric Field Penetrate Non-Conducting Sheets?

    http://noether.physics.ubc.ca/Physics153/assignt222k6.pdf ^ number 2. I don't get this problem. if the plastic sheets are non-conducting, does that mean the electric field can't penetrate the sheets? and how should i do this problem?
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    Airplane and Conveyor Belt Debate

    would the plane take off? Can this plane take off given no winds? Theres a quite a bit of discussion on this over at neowin. http://www.neowin.net/forum/index.php?showtopic=413477
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    How can I find the value of phi in a simple harmonic motion equation?

    ah yes, i see, it should be v = -A ωsin(ωt + φ), but that's just a typo, i actually had this equation when i wrote it down on paper. But i still don't know how to find phi
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    How can I find the value of phi in a simple harmonic motion equation?

    http://noether.physics.ubc.ca/physics153/assign72k5.pdf I don't get number 1 c, which equation do i use? and in general, how would I be able to find phi? OK, i figured i should find the first derivative of the displacement formula, which becomes v = -Asin(wt + phi) but that still undoable, how...
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    How Do You Calculate Work and Internal Energy from a Thermodynamic Graph?

    http://noether.physics.ubc.ca/physics153/assign52k5.pdf number 3. For part d I'm finding the work by looking at the area under the graph, and a friend of mine used 1.5kdT, which also seems to make sense in this situation, but we're getting 2 different answers. For the change in internal energy...
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    Quick question 1st law thermodynamics

    What is the equation to find the change in heat of a system that is isothermal? And also, for a PV graph, if the state of the system loops back onto itself, as in it starts at a and ends at a, is the total change in internal energy always 0?
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    Calculating Heat Transfer in Copper & Ice Layers

    well supposedly you're suppose to use some integral crap, but i dun know how to do it.
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    Calculating Heat Transfer in Copper & Ice Layers

    First off, you must be in phys153 in UBC, because I got the exact same problems. For 1, you first find out the energy it took to boil all the water, and that's Lf*m. You then find find the power by dividing the energy you just found by the time. Since H measures the heat transfer for...
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    Difficult problem, need help

    difficult problem, need URGENT help A small pond has a layer of ice 1cm thick floating on its surface. (a) If the air temperature is −10C, find the rate in cm per hour at which ice is added to the layer. The density of ice is 0.917g/cm3 and its thermal conductivity is 0.592 W/mK. (b) How long...
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    How much heat is transferred and at what temperature?

    A 150g copper bowl contains 220g of water. Both bowl and water are at 20 degrees C. A very hot 300g copper cylinder is dropped into the water. This causes the water to boil, with 5g being converted to steam, and the final temperature of the entire system is 100 degrees C. a) how much heat is...
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