Recent content by davidphysics

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    Light Intensity: Calculating Energy Flux through an Area Element

    Yea we told our teacher, so now the t= 4 seconds, and obviously now the problem is super easy. W=Pt W= 40 W (4 s) W=160 J
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    Light Intensity: Calculating Energy Flux through an Area Element

    [SOLVED] Light Intensity question The light (electromagnetic) output of a bulb is 40 W. How much energy passes through a 40 cm^2 area element aligned perp. to the light rays? I know that I = Power/Area, but I thought that Power = W(aka. energy) /t , and the problem has no reference to time...
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    Calculating Final Speeds of Colliding Pucks on an Air-Hockey Table

    Nevermind - I figured it out. I was making it much too difficult. All I had to do was Po=Pf for the horiz and vert, and solve that set of equations.
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    Calculating Final Speeds of Colliding Pucks on an Air-Hockey Table

    Hi. I am still having trouble and would like help. Its not working out. Thanks
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    Calculating Final Speeds of Colliding Pucks on an Air-Hockey Table

    I mean the initial VERT momentum. But thanks for "The initial kinetic energy is not zero either, since A is moving." Can't believe I screwed that up. I don't have any more time now, but I'll work on that tomorrow and will come back to this forum later. Thanks! and cya
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    Calculating Final Speeds of Colliding Pucks on an Air-Hockey Table

    Wow, then that image is very deceiving... thanks for your help -Everyone else JUMP IN! :) Just thinking of it that makes perfect sense, now I see how these pictures mess with your mind. Disregard everything above, yea so the Vert momentum up = vert momentum down
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    Calculating Final Speeds of Colliding Pucks on an Air-Hockey Table

    O didn't realize that, please read my post that I just posted a second ago, and I'll put the image on imageshack. POSTED:http://img135.imageshack.us/img135/9303/0732jj6.gif And when I plug in the values for "v" in those formulas I should use for example Vacos65 and Vasin65 for the horiz and...
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    Calculating Final Speeds of Colliding Pucks on an Air-Hockey Table

    And when I plug in the values for "v" in those formulas I should use for example Vacos65 and Vasin65 for the horiz and vert respectively, right? For some reason I keep getting the Vert for a and b=0, because both the initial momentum and kin energy=0. So when I solve I get Vert: Va=Vb=0... I...
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    Calculating Final Speeds of Colliding Pucks on an Air-Hockey Table

    Ok sorry let me explain what I've gotten to... Basically I've set up both horizontal and vertical equations for both Po=Pf and Ko=Kf. Before I go any further, am I correct to assume that it is elastic and that the kinetic energy is conserved? To be honest I don't wan't to use up my 4 trys on...
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    Calculating Final Speeds of Colliding Pucks on an Air-Hockey Table

    Hey. This is my first post... here's my question [Diagram Attached]: The drawing shows a collision between two pucks on an air-hockey table. Puck A has a mass of 0.028 kg and is moving along the x-axis with a velocity of +5.5 m/s. It makes a collision with puck B, which has a mass of 0.068 kg...
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