Recent content by Bacat

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    When is it inappropriate to report Pearson correlation coefficients?

    Thanks for the response! I'm not familiar with the antilog transform. I think I should make the following transformation: Date -> Transformed Data 0 -> 1 1 -> 10 2 -> 100 etc.. Is this correct? Won't this lead to some enormous numbers later? For example: 17 -> 100,000,000,000,000,000 I...
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    When is it inappropriate to report Pearson correlation coefficients?

    I am writing a paper publishing scientific data. My background is chemistry but I have taken a couple of stat classes. In my opinion, one of the biggest deficiencies in modern research publications is the improper use of statistics. I hope to avoid making this mistake, but I need your help...
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    Calculating theoretical heating rate of sand

    I have a small steel cylinder centered inside a larger steel cylinder. The remaining space is filled with 60% silica sand and 40% air. I am heating the larger cylinder in a furnace at a known heating rate and I want to calculate the theoretical rate of heating of the internal cylinder. This is...
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    How Do You Calculate Cooking Intensity from Cooling in an Oven Cycle?

    Please help if you know the answer.
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    How Do You Calculate Cooking Intensity from Cooling in an Oven Cycle?

    Should I ask the question in a different way? Or did Memorial Day just derail the forum? :)
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    How Do You Calculate Cooking Intensity from Cooling in an Oven Cycle?

    I have a block of food in an oven and I want to calculate the "cooking intensity" of the block during a controlled oven cycle. The cycle of the oven is that it heats at 5 degrees (C) per minute, holds the temperature at 300C for 1 hour, and then shuts off the oven to cool to room temperature. I...
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    Calculate smallest pore that will admit water

    I think I should just set theta equal to 90 degrees then, ie the limiting case. Then the pressure of interest is just the surface tension divided by the pore size. I think I just need to match this to atmospheric pressure. Another question is whether a drop of water will have significant...
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    Calculate smallest pore that will admit water

    I am conducting some hydrophobicity research with dried powders. I have known mixtures of fluid from which I can calculate surface tension. I have data about the powders regarding which mixtures easily wet the surface and which bead up into drops. I also have BET surface area histograms which...
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    Why Is My Calculation of Magnetic Potential Energy Incorrect?

    Just think of work as the amount of energy necessary to apply a force for a certain amount of time. If you want to throw a ball 5 feet, you need a certain amount of energy (or work). To throw the ball 25 feet, you need five times as much. After you have intuition about work as a force that you...
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    Motion of a Boat: Calculating Mass, Distance & Retarding Force

    Sorry if I'm confusing you. When I solve it, I get: a=\frac{3}{t(1 + 3 \beta t)} To take the derivative of 1/v the easiest thing is to invert it so you can v in the numerator.
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    Motion of a Boat: Calculating Mass, Distance & Retarding Force

    \frac{1}{at}=\frac{1}{3}+\beta t To check your answer, let: a= \frac{3 + \beta t^3}{3} \frac{1}{t*\frac{3 + \beta t^3}{3}} = \frac{1}{3}+\beta t This simplifes (sort of) to: \frac{3}{3t+\beta t^4}=\frac{1}{3}+\beta t Looking at the variable t, we are saying that t to the negative...
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    Equilibrium. How to solve for four variables?

    The easiest way to think about this is to break it into parts. Instead of solving for multiple unknowns just solve for part a. The vertical component of tension must be perfectly balanced by the vertical component of the torque of the beam. Same goes for the horizontal tension. You can...
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    Motion of a Boat: Calculating Mass, Distance & Retarding Force

    Hmm... That's not what I get...Assuming you start from here... \frac{1}{at}=\frac{1}{3}+\beta t You can check your answer by substituting what you got for a into the original equation for a (the equation above). You should get the two sides equal to each other if you have the right a...
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    Rotational and translational motion of a ruler on a pivot

    @longball, the force exerted on the ruler will cause the ruler to spin even if it is much lighter than the ruler's weight. If the force was greater than the ruler's weight then the ruler could be "broken off" the pivot point. I think the point of the question was just to assume that the applied...
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    Rotational and translational motion of a ruler on a pivot

    You are right that if there is no friction the ruler will continue spinning. As for the second part, remember that there is a difference between the "ruler's motion" and the "motion of the ruler's center of mass". Does this help?
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