Recent content by cdymdcool

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    How Long Ago Did the Supernova Occur That Created Earth's Heavy Elements?

    All the very heavy atoms found in the Earth were created long ago by nuclear fusion reactions in a supernova, an exploding star. The debris spewed out by the supernova later coalesced to form the sun and the planets of our solar system. Nuclear physics suggests that the uranium isotopes 235U...
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    What direction should the electric field point in a velocity selector?

    So the B-field Force is going out of the page, the electric field should be the opposite, going into the page. If particle is positive or negative, the electric field point will both going into the page? But the answer key says down, is it from different perspective?
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    How to determine the potential difference?

    1. A horizontal rod(oriented in e-w direction) is moved northward at constant velocity through a magnetic field that points straight down. 2. Why is the west end of the rod is at higher potential than the east end? 3. I have no idea how to obtain any information about V.
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    What direction should the electric field point in a velocity selector?

    A velocity selector consists of a charged particle passing through crossed electirc magnetic fields. The forces exerted by these fields are in opposite directions, and only particles of a certain velocity will move in a straight line. In the following, disregard the magnitudes of the fields...
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    Solving 1.5 Moles Monatomic Ideal Gas at 314K - No Calc

    1. 1.5 moles of a monatomic ideal gas is enclosed at 314K. THe initial volume of the gas is 3m^3. The gas is comperssed isothermally to a final volume of 1m^3. How much heat is removed from the gas. So deltaU=0, Q=-W, So we have to know the area under the P-V curve, but how can we get...
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    What's the rms speed of the molecules?

    I use the formula v = square root of(3kT/m), which k stands for boltzmann's constant and m stants for the mass of molecule.
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    What's the rms speed of the molecules?

    so nm equals the #of moles times its mass, what isn't the #of moles still unknow?
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    What's the rms speed of the molecules?

    1. A canister containing 150kg of an ideal gas has a volume of 8 m^3. If the gas exerts a pressure of 5*10^5 Pa, what's the rms speed of the modecules? I can't get the temperature of the canister...
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    Why does the charge uniformly distributed on the surface of the sphere only?

    But why aren't the charges uniformly distributed throughout the sphere?
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    Why does the charge uniformly distributed on the surface of the sphere only?

    1. A solid conducting sphere is given a positive charge Q. Why is the charge uniformly distributed on the surface of the sphere only? Homework Equations 3. I know there are electron clous where electrons hang out, but what happen when the sphere is given a postive charge? I don't...
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