Recent content by delongk

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    Threshold wavelength photoelectrons

    how does that help? i still don't understand.
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    Threshold wavelength photoelectrons

    the energy would be equal to the work function at 600nm because when the wavelength is at the threshold the energy is always equal to the work function.
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    Threshold wavelength photoelectrons

    With what speed will the fastest photoelectrons be emitted from a surface wih threshold wavelength of 600nm when the surface is illuminated with light of wavelength of 400nm?
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    Fastest Photoelectron Emission: 400nm Light on 600nm Threshold Surface"

    With what speed will the fastest photoelectrons be emitted from a surface wih threshold wavelength of 600nm when the surface is illuminated with light of wavelength of 400nm?
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    Speed of a photon with wavelength = 500nm?

    Well that makes it easy. Thank you tons for clearing that up... something so simple, you think they'd tell you that in the book. Thanks again!
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    Speed of a photon with wavelength = 500nm?

    What is the speed and momentum of a photon with wavelength 500nm? I found momentum by wavelength = h/p but how do I find velocity?? Please help. Thanks. I don't know how to do it without a mass. Kristin
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    How Do You Calculate Proton Speed and Momentum in Special Relativity?

    That's where I went wrong... I kept putting 2000MV into the KE and got the wrong answers... but I have to convert it to J. Thanks!
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    How Do You Calculate Proton Speed and Momentum in Special Relativity?

    Is 2000MV equal to the KE then?? How do you find KE to use that to find v? ANd I have studied for a week... I just couldn't get this one problem when I was reviewing this morning.
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    How Do You Calculate Proton Speed and Momentum in Special Relativity?

    Special Relativity I NEED HELP ASAP! Find the speed and momentum of a proton (m=1.67*10^-27) that has been accelerated through a potential difference of 2000MV. Give your answers to three sig figs. Ans: .948c and 1.49*10^-18kg m/s I keep trying different ways to get this, but keep getting...
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    Electric Force Question and Spheres

    Three identically charged spheres A, B, and C, each with a charge of +3.0 * 10-7 C, are located at the corners of a triangle whose sides are 30 cm long and all the angles are 60 deg. What is the net force acting on sphere A? I figured the X coordinates cancel each other out. For the Y...
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    Solving Gauss' Law: Find Flux of 443C Ball with 7.97cm Radius

    no i have no idea what to do... i need step by step. and everything i read said you don't need the radius.
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    Solving Gauss' Law: Find Flux of 443C Ball with 7.97cm Radius

    This is the website I am getting the questions from: http://www.dctech.com/physics/help/problems.php?problem=electric-gauss
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    Solving Gauss' Law: Find Flux of 443C Ball with 7.97cm Radius

    Another example on the webpage is: A small charge is at the center of a 9.77 cm radius ball. If 8.322 E-8 N.m2/C passes through the ball's surface, how much charge is at the center? and the answer is 749C. I don't get this one either. I am assuming the use the same equation.
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    Solving Gauss' Law: Find Flux of 443C Ball with 7.97cm Radius

    I copied and pasted it so I know that is right. And I keep getting the wrong answer for ALL of the examples... which are all similar to that one.
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    Solving Gauss' Law: Find Flux of 443C Ball with 7.97cm Radius

    I keep finding that flux= q/Eo and so I put 443 in for q and 8.85*10^-12 for Eo and get 5.006*10^13.
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