Which of the following statements is true of classical physics? a. it is no longer applicable in solving physics problems. b. it is an approximation of quantum physics on larger scales. c. it is necessary to describe the motion of objects at the molecular level. d. it is more useful than quantum physics for objects moving at extremely fast speeds.

Two 1.20-m nonconducting wires meet at a right angle. one segment carries + 2.50 µc of charge distributed uniformly along its length, and the other carries - 2.50 µc distributed uniformly along it, as shown in fig. 21.50. ( a. find the magnitude and direction of the electric field these wires produce at point p, which is 60.0 cm from each wire. ( b. if an electron is released at p, what are the magnitude and direction of the net force that these wires exert on it?