1. C

    Mass of a box been pushed taking friction into account.

    This feels like a really basic question so i feel like I'm making an assumption that I shouldn't be. Max fs=us*N Fk=uk*N N=mg For the box to start to move Fk must equal Fs. So I can rearrange for m from there us*75*9.81=uk*9.81*m but this answer isn't ending up anywhere near the correct answer...
  2. I

    Box on a wedge, no friction

    A box with mass m=0.5kg appears on top of a wedge with mass M=3,5kg. Wedge is inclined by 35°. Assume no friction exists anywhere and calculate acceleration of both block and wedge. How to solve this? Is it possible to solve this using momentum?
  3. C

    Box w/ horizontal force up incline w/ friction

    Alright, I have spent the last 9 hours trying to figure out how on earth I am supposed to determine the horizontal force in this problem. I've got to be missing something obvious. I know that the answer to...
  4. R

    Convection in isolated box (HELP!!!)

    Hi, I do not have much knowledge about this stuff (just basic things), but I need to know something. How do I calculate, how many cooling elements (bags of ice) do I need to maintain the temperature products (0°C-4°C) inside an isolated box for 24 hours? Depends on the cooling elements...
  5. R

    Particle in a cubic box with momentum operator

    A particle moving in 3D is confined to a cubic box of edge length L with one corner at the origin and edges lined up with the positive coordinate axes. Using separation of variables, solve the momentum eigenvalue equation P ⃗_ϕ (r ⃗ )=p ⃗_ϕ (r ⃗ ) (see attachment for better representation of...
  6. Troll

    Thinking outside the box

    Is their any history of mind experiments taking the perspective of an observer outside of space/time? Who, when and a reference would be awesome... thx!
  7. R

    [SOLVED] A man pushes a 22 kg box across a frictionless floor.

    I need help on how to start with these questions. I do know that i have to use the kinematics equations.
  8. E

    Particle in a spherical box

    Hello everybody: I have a problem with the Schrödinger equation in 3D since I'm trying to solve the problem of the energy of a particle inside a spherical box of radius "a" where inside the sphere the potential energy is zero and out the sphere is infinite. First of all, I was looking at...