Recent content by mnphys

  1. M

    Prediction interval - what did I do wrong?

    Ok. I was kinda wondering if maybe the book was wrong in this case. Thanks for your reply!
  2. M

    Prediction interval - what did I do wrong?

    Homework Statement A random sample of 100 automobile owners in the state of Virginia shows that an automobile is driven on average 23,500 kilometers per year with a standard deviation of 3900 kilometers. Assume the distribution of the measurements to be approximately normal. Construct a 99%...
  3. M

    Finding k in a probability density function

    Ok. I'll roll with that... Thanks, guys (or possibly gals)!
  4. M

    Finding k in a probability density function

    The book does say "0 < x" and "y < 1" but maybe you're right and that should be assumed? It does work out perfectly if you use 0 to 1 as the ranges.
  5. M

    Finding k in a probability density function

    Homework Statement Let X, Y, and Z have the joint probability density function f(x,y,z) = kxy2z for 0 < x, y < 1, and 0 < z < 2 (it is defined to be 0 elsewhere). Find k. Homework Equations Not sure how to type this in bbcode but: Integrate f(x,y,z) = kxy2z over the ranges of x (zero to...
  6. M

    Cart/putty collision question (conservation of momentum)

    Thanks! This was one of those questions you spend hours on and then when you finally realize what you're looking for it's absurdly simple. I assumed that the velocity of the second cart did not change after dropping the putty on it - wrong, of course. But without knowing how much the putty...
  7. M

    Internal energy of a decaying atom (simple energy problem)

    Thank you! I will be sure to follow that template if I have to ask any more questions. And your help was critical in solving this problem; given the mass of both particles and the velocity of one particle it's a simple matter of finding the velocity of the second particle and then calculating...
  8. M

    Internal energy of a decaying atom (simple energy problem)

    Sorry, I thought I was using the template? I posted the question first, then the equations, then the attempt. If I didn't follow the rules I apologize. I know nothing about the alpha particle's speed; all the information I was given was posted there. I thought it odd that they didn't mention...
  9. M

    Cart/putty collision question (conservation of momentum)

    Homework Statement A 1.0-kg standard cart collides on a low-friction track with cart A . The standard cart has an initial x component of velocity of +0.40 m/s , and cart A is initially at rest. After the collision the x component of velocity of the standard cart is +0.20 m/s and the x...
  10. M

    Internal energy of a decaying atom (simple energy problem)

    This is my first time here. Sorry if the formatting is a bit off. This is one of a few questions I am having difficulty with. I am not asking for any answers; and I have definitely done the work - multiple times - but have not been able to find the correct answer. Q) A uranium-238 atom can...
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