A straight, stiff, horizontal wire of length 44.5 cm and mass 43.0 g is connected to a source of emf by light, flexible leads. A magnetic field of 1.72 T is horizontal and perpendicular to the wire. Find the current necessary to float the wire, that is, the current such that the magnetic force balances the weight of the wire.

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

Two point charges are on the y axis. a 3.90-µc charge is located at y = 1.25 cm, and a -2.4-µc charge is located at y = −1.80 cm. (a) find the total electric potential at the origin. v (b) find the total electric potential at the point whose coordinates are (1.50 cm, 0). v

Two waves maximally constructively interfere at a point in space. among the options below, select the possible value of their phase difference at that point in space. a. zerob. πc. π/2d. not determinable by the information provided