Recent content by Dars

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    Heisenberg Uncertainy Principle

    Homework Statement Modern electron microscopes used in biological research emit a beam of electrons with a velocity of 1.5x108 m/s a. What is the wavelength of an electron in the beam? b. The wavelength of the particle determines the resolution of the microscopy. Assume that you desire a...
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    Supercooled water freezes. Is this a spontaneous process?

    Supercooled water freezes. Is this a spontaneous process?? Homework Statement "one mole of supercooled water at -10degC freezes reversibly to ice at -10degC at constant P of 1500atm. The system is at chemical equilibrium. Assume that ΔH_fusion is independent of temperature. Also assume that...
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    Dont understand how p=nRT/V relates to dU = C_VdT

    Homework Statement WIKI says: "In case of an ideal gas, p = NkT / V which implies that dU = CvdT, i.e. the internal energy of an ideal gas can be written as a function that depends only on the temperature." I don't understand the bolded part.. What is the relationship? thanks Homework...
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    Why is \( C_V \) Relevant in Isothermal Expansion Calculations?

    Homework Statement One mole of an ideal monoatomic gas initially at 300 K is expanded from an initial pressure of 10 atm to a final pressure of 1 atm. The molar heat capacity for constant volume for the gas is C_V = 3/2(R). Calculate ΔU, ΔH, q, w, and the final temperature (Tf) for an...
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    Please check my work (ice melting in cup) thanks

    Homework Statement You have 0.9 L of water in an insulated (thermally isolated) cup at 20 ºC. You add 360 g of ice at −20 ºC in the cup to cool the water. Describe the final state of your system in terms of (i) number of moles of ice (ii) number of moles of water and (iii) the final...
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    Please check my work energy required to raise temp by 10degthanks

    Homework Statement You want to heat 1 L of water by 10 ºC, and so you heat it with a mechanical egg beater that is powered by a 1 kg mass on a rope over a pulley. How far does the mass have to descend to supply enough work for heating the water? Homework Equations |work| = mg(x_f - x_0)...
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    Cant grasp difference between infinitesimal change and macroscopic change

    What does infinitesimal change in V mean? Can someone please illustrate with simple example. Lecture notes say infinitesimal change in V = dV And large change in V is delta V.. I don't understand what it means though
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    What Does Fixed Volume Refer to in Thermodynamics?

    simple question about "fixed volume" What exactly does "fixed volume" mean in thermodynamics, for a liquid? Does it mean that the container volume is fixed or that the volume of water is fixed, or that the volume of both the container and the water is fixed? This is confusing me because...
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    Termochem problem. Work required to heat water

    Homework Statement "You want to heat 1 L of water by 10 ºC so you heat it with a mechanical egg beater that is powered by a 1kg mass on a rope over a pulley. How far does the mass have to descend to supply enough work for heating the water? Homework Equations delta T = 10degC delta...
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    Rayleigh's critereon problem please check my work

    Homework Statement a telescope has a diameter of 8m. A double star 6000 light years away is viewed. what must be the min distance apart (in ly) of the two stars for their images to be distinguished if light of wavelength 500nm is used? Homework Equations theta = 1.22 (lamda/D) D =...
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    What is the relationship between counting rate and rate of decay?

    what is "counting rate"? Homework Statement Is "counting rate" the same as "rate of decay"? This problem asks about counting rate, but i can't see this term anywhere in my physics book.. Is it like an alternate term for "rate of decay" (also, counting rate isn't even on wikipedia)...
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    Two slit interference question dont know how to begin

    Homework Statement Two slit interference question: A screen is 2.2m from two slits. The distance from point P to point R (the central maximum to the 2nd dark band) is 1.6mm. This is what the pattern looks like (l) means light band... (d) means dark band ......P...R (d) (l) (d) (l) (d)...
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    What is the minimum height for a mirror to see full image?

    Homework Statement I am 2 meters tall and I want to see my full image in a mirror. What is the minimum height the mirror should be? Homework Equations Why shouldn't min height be also 2m, because no magnification (plane mirror) ?? The Attempt at a Solution
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