The diagram shows a nail before and after a procedure was done. which statement best explains what was likely done to the nail? a) it was made to conduct electricity, which caused the domains to randomize and the nail to become nonmagnetic. b) it was rubbed with a magnet, which caused the domains to line up and the nail to become magnetic. c) it was struck repeatedly, which caused the domains to randomize and the nail to become nonmagnetic. d) it was heated, which caused the domains to line up and the nail to become magnetic.

A23 kg log of wood begins from rest, 300 m up a sluice (a water track used to transport logs, think of it as an inclined plane with negligible friction) inclined at 20° to the horizontal. after it reaches the flat waterway at the bottom it collides elastically with a 100 kg block of wood initially at rest near the base of the incline. (a) how long does it take the 23 kg log to travel down the incline? (b) what is the speed of the 23 kg log at the bottom of the incline? (c) what are the velocities of both blocks of wood after the collision? (d) what is the total kinetic energy before the collision? (e) what is the kinetic energy of the 23 kg log after the collision? (f) what is the kinetic energy of the 100 kg block of wood after the collision? (g) what is the total kinetic energy after the collision? (h) compare the total initial and total final kinetic energies. is this consistent with what you would expect for elastic collisions? explain!

If an atom contains 11 protons in its nucleus, predict the element with the atomic number and electronic configuration. will the number of electrons remain the same during the chemical reaction in such an atom? explain.

Where do magnetic lines of force enter earth?