A wire of length L is wound around an iron cylinder mounted on a base. The two ends of the wire are connected to a battery via a switch that is initially open. A metal ring with a diameter larger than that of the cylinder sits on top of the coil. What happens to the metal ring when the switch is closed?

What is hidden during a lunar eclipse? isn't the moon hidden?

Agas initially at p1 = 1 bar and occupying a volume of 0.5 liter is compressed within a piston–cylinder assembly to a final pressure p2 = 4 bar. (a) if the relationship between pressure and volume during the compression is pv = constant, determine the volume, in liters, at a pressure of 3 bar. (b) repeat for a linear pressure–volume relationship between the same end states. reference

The man of mass m1 and the woman of mass m2 are standing on opposite ends of the platform of mass m0 which moves with negligible friction and is initially at rest with s = 0. the man and woman begin to approach each other. derive an expression for the displacement s of the platform when the two meet in terms of the displacement x1 of the man relative to the platform.