The disk on the bottom has a rotational inertia of I0 and is spinning clockwise on a horizontal surface having negligible friction at an angular speed of 3ω0 . The top disk is then dropped directly on top of the bottom disk. The top disk has a rotational inertia of I0 and was initially spinning counterclockwise at an angular speed of ω0 . If the initial total kinetic energy of the two-disk system was E0 , what will the kinetic energy of the system be once the objects reach a common angular speed?

During physical science, ms. greene challenged her students to produce an energy transformation. james and jill wrapped a 4-inch nail with a coil of fifty turns of wire. they connected one end of the coil to one terminal of a knife switch. they connected the other terminal of the knife switch to the battery. finally, they connected the end of the coil to the other terminal of the battery. james held the tip of a 1-inch nail near the flat end of the 4-inch nail. jill closed the knife switch quickly and then opened it. the 1-inch nail was pulled toward the 4-inch nail. what is the best explanation of why the nail moved? a) electrical energy was converted to mechanical energy in the 1-inch nail. b) the 4-inch nail became an electromagnet and the magnetic force attracted the 1-inch nail. c) the electric current in the 4-inch nail was converted to mechanical energy in the 1-inch nail. d) the 4-inch nail had a positive charge and the 1-inch nail had a negative charge. opposites attracted.

The transfer of heat through the movement of a gas or liquid a. convection b. conduction c. radiation

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final