Recent content by spaghed87

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    Pressure on a wall due to n N2 molecules (close to ans)

    Awesome, I figured it out. I used (2)*(number of particles)*(mass)*(velocity)/(Area). They only gave a formula for the 3-D volume in my book. Thanks for the help!
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    Pressure on a wall due to n N2 molecules (close to ans)

    I can't see how the volume is wrong though. 20cm^2/100^2= 0.002m^2. Another person who attempted the problem was using the same value for the volume as me. I've got the concept of elastic and inelastic collisions down. I learned it in my first calc. based physics class. More help would be...
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    Pressure on a wall due to n N2 molecules (close to ans)

    Homework Statement 4.60×1023 nitrogen molecules collide with a 20.0cm^2 wall each second. Assume that the molecules all travel with a speed of 450m/s and strike the wall head on. What is the pressure on the wall in pascals (Pa)? Homework Equations p=(1/3)*(N/V)*(m*v_rms^2) where...
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    Length of the box based on the fringe pattern? I think I'm close.

    Homework Statement The figure shows a neutron in a one-dimensional box. If the right end of the box is opened, the neutron travels out of the box, impinges on a double slit, and is detected 2.0 m behind the double slit. Repeating the experiment over and over produces the fringe pattern shown...
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    What is the atomic spacing D of this crystal?

    Homework Statement X rays with wavelength 0.10 nm are incident on a crystal with a hexagonal crystal structure. The x-ray diffraction spectrum is shown in the figure. Figure: What is the atomic spacing D of this crystal? (in nanometers) Homework Equations The Bragg...
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    Radius of curvature of the cornea

    I did f*(n-1) = R even before you mentioned the equation in that form. Maybe the masteringphysics website is off. I derived that formula by taking s=f and s' being equal to inifinity for an answer of 1.02cm (we are on the same boat). Yes, it is focusing into a medium with an index of 1. This...
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    Radius of curvature of the cornea

    I guess you could approach it from the lens makers... I don't see how though. I'm given only one radius... in your formula that needs to be a R subnot 1 and 2. Also, I'm dealing with two index of refraction values. With the amount of known values I have I cannot seem to piece them together into...
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    Radius of curvature of the cornea

    Are you implying that it is 2*f=R? 6.0cm is not the right answer if so. That only applies for mirrors right? They seem to be indicating the "air" and the "aqueous humor" in the problem... both of which have given index of refractions in the book. I believe the equation used to solve this problem...
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    Radius of curvature of the cornea

    Homework Statement The cornea, a boundary between the air and the aqueous humor, has a 3.0cm focal length when acting alone. What is its radius of curvature? Homework Equations n(1)/s + n(2)/s' = (n(2)-n(1))/R where, n is the index of refraction (unitless), s' is the img dist (cm)...
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    Time needed for a transverse wave to propagate on a string

    I ended up solving it differently by finding t_1, t_2, t_3, and then by adding all of the times for the time overall. Woot extra credit for me. Thanks for the help. Time for the test tomorrow. :smile:
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    Time needed for a transverse wave to propagate on a string

    I was thinking I had 1/s for time instead of s but I was having a brain fart. So, if I take the inverse of that equation it should be right then?
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    How Do You Create a Scale Drawing of a Hot Air Balloon with Mints as Passengers?

    A scale drawing is simply a drawing of the real object however it is reduced in size and put on paper. You can use parameters such as making every line on your paper equal to one inch even though realistically the space between a line on your paper is not an inch. I would use graph paper if...
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    Time needed for a transverse wave to propagate on a string

    Homework Statement Consider a string of total length L, made up of three segments of equal length. The mass per unit length of the first segment is mu, that of the second is 2*mu, and that of the third mu/4. The third segment is tied to a wall, and the string is stretched by a force of...
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    The focal length of a mirror. Help me maybe?

    Wow, thanks for the figure. My online homework still said that the answer of 160cm was still the wrong answer. I believe it is because we need to consider the thin lens equation after finding the obj and img distance. I cannot see how you are getting the focal length to be 160cm? I'd be happy if...
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    The focal length of a mirror. Help me maybe?

    Homework Statement Mastering physics problem 23.76 difficulty rating: two bars=difficult A 2.0-cm-tall object is placed in front of a mirror. A 1.0-cm-tall upright image is formed behind the mirror, 180cm from the object. What is the focal length of the mirror? Homework Equations...
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