Recent content by Randomer Guy

  1. R

    Elementary physics of falling bodies.

    But Y's ability to catch that mass is a function of the mass in the first place. So the mass is less important than the amount of energy relative to the mass.
  2. R

    Elementary physics of falling bodies.

    X is falling from 11 meters. Y is an object designed to support X+(unknown variable) against gravity when it is stationary. How much force/resistance must Y apply to X to stop its downwards motion? Assume X+(unknown variable)= X*2 What is not known in this case is the ending...
  3. R

    Elementary physics of falling bodies.

    Check your private messages. The question ultimately hinges on how much force, relative to the mass, is required to stop the fall. The thing doing the catching is designed to hold the falling mass stationary plus some. I am trying to demonstrate that the kinetic energy/force imparted of...
  4. R

    Frictional Force/Kinematics Problem

    Random information about trains: Most "Deisel" engines aren't really powered by diesel engines. They are electric engines that use massive deisel generators for power. Not exactly pertinent, but interesting anyways.
  5. R

    Frictional Force/Kinematics Problem

    Yup. the other posters are right. You have to have either: the coefficient of friction ----this will allow you to figure out the time and distance or the time it decellerated to a stop. As given, you do not have sufficient information to solve the problem.
  6. R

    Elementary physics of falling bodies.

    I do know that the maximum acceleration is that of gravity though. :biggrin:
  7. R

    Elementary physics of falling bodies.

    Going back to the OP, the only known is that the object is moving. I think the resistance is rather small compared to the energy of motion, so the ending velocity is probably pretty close to what one would expect from a free fall. (say about 75% of g, acting over a known distance)
  8. R

    Elementary physics of falling bodies.

    Ah, there is the burn. I am trying to get the acceleration or a close approximation of it. The people I am talking to say that it is not reasonable to simply reduce or "fudge" the gravitational acceleration to account for some unknown quantity of resistance. The falling object is...
  9. R

    What is the final velocity of a falling body?

    I would rather not get into exactly what is being discussed and to whom. It is the kind of thing that can get touchy with people. Let's just say that I am talking to people with very little knowledge of physics and critical thinking.
  10. R

    What is the final velocity of a falling body?

    This is exactly the same as the calculations for an object in free fall by the way. :wink: I have done the calculations, but the people I am talking to don't really believe they apply in the case in discussion. They seem to think I am missing something and that the calculations are...
  11. R

    What is the final velocity of a falling body?

    PE = mgy where m is the mass of an object, g is the acceleration due to gravity, and y is the distance the object is above some reference level But, I assume you are asking for a reason (thanks for helping, by the way), so let's go with this. PE=m(9.8 meters/sec/sec)(3 meters) or...
  12. R

    What is the final velocity of a falling body?

    that goes back to the kinetic energy equation. Would the ultimate height be irrelevant, if all one is doing is calculating the energy after 10 meters? I am thinking of an object at great height, but only considering the first 3 to 11 meters of its fall. I want to eventually get at a...
  13. R

    What is the final velocity of a falling body?

    PE = mgy where m is the mass of an object, g is the acceleration due to gravity, and y is the distance the object is above some reference level. I am really trying to find energy in terms of the mass involved, because I can't even reasonably get to the mass, but the mass relative to...
  14. R

    What is the final velocity of a falling body?

    Homework Statement It is possible to calculate the velocity of falling bodies (ignoring air resistance of course) using a gravitational acceleration constant. Assume: You don't know what the resistance is. The object started at rest. You DO know there is downwards motion. You don't...
  15. R

    Elementary physics of falling bodies.

    It is possible to calculate the velocity of falling bodies (ignoring air resistance of course) using a gravitational acceleration constant. If there is some other resistance, other than air, is it reasonable to simply reduce the acceleration by some amount to account for that resistance, if...
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