A student has an isolated system of charged particles. The student wants to calculate the change ΔUE in the electric potential energy of the system between two instants in time but cannot do that directly, since the student does not have any information about the magnitude of the charges. Which of the following correctly describes a mathematical routine, if any, that can be used to determine ΔUE? Gravitational effects are negligible.

(A) Calculate the change AK in the total kinetic energy of the particles. This will be equal to - AUE
( B ) Calculate the change AK in the total kinetic energy of the particles. This will be equal to AUE
с Calculate the average kinetic energy Kavy of the particles during the time interval between the two instants. This will be equal to AUE-
(D) The change in electric potential energy of the system cannot be determined without knowing the magnitudes of the charges.

Awind turbine is initially spinning at a constant angular speed. as the wind's strength gradually increases, the turbine experiences a constant angular acceleration 0.173 rad/s2. after making 2870 revolutions, its angular speed is 132 rad/s. (a) what is the initial angular velocity of the turbine? (b) how much time elapses while the turbine is speeding up?

When a book falls from a shelf to the ground without anyone pushing on it, no work is done on the book. true or false

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.