# planes

1. ### Submerge planes

I'm having trouble with the following problem, can anyone help? Refer to attached picture. A 25-mm thick steel-gate of 15-mx8-m size, specific gravity of 7.8 is hinged, as shown in the figure below, to store flash-flooding water. The density of water, at standard temperature condition, is...
2. ### Circular motion in two planes problem

Hi everybody, I have a problem that has got me puzzled as to how to tackle it. The problem reads as follows - A small bead can slide without friction on a circular hoop that is in a vertical plane and has a radius of 0.100m. The hoop rotates at a constant rate of 4.00rev/s about a vertical...
3. ### Equation of the line intercepting two planes

I have two equations of planes . Lets say ax + by + cz = k and dx +ey + fz = k' When solving these two equations I should get an equation for a line. Now if I assume z = t then I can find x, y in terms of t parameter. That will give me a parametric equation for the line. But the problem is...
4. ### Quadrupole and Octopole planes

I am writing a research review on dark matter and cosmology. I ran into a paper (see arXiv) describing the problems faced by LCDM cosmology. One such problem related to the alignment of the low multipoles (as L. Perivolaropoulos puts it). The exact phrase used in the paper is I am...
5. ### Electric Field between two infinitely long parallel planes

"Two infinite planes of charge lie parallel to each other and to the yz plane. One is at x = -4 m and has a surface charge density of σ = -3.2 µC/m2. The other is at x = 4 m and has a surface charge density of σ = 5.8 µC/m2. Find the electric field for the following locations." (a) x < -4 m...
6. ### Planes fying north and east

I have been posed a problem which on the face of it seems trivial, but the more you look, the wackier it gets. I'm in a complete muddle with frames of reference... Can anyone give me the proper Physics behind an answer? Two planes depart from JFK International Airport at the same time. One...