Acopper wire has a square cross section 2.3 mm on a side. the wire is 4.0 m long and carries a current of 3.0 a. the density of free electrons is 8.5 x 1028 m3
part a find the magnitude of the current density in the wire. express your answer using two significant figures. vaxd a/m2 j request answer submit part b find the magnitude of the electric field in the wire. express your answer using two significant figures. vaxo ? v/ e= submit request answer part c how much time is required for an electron to travel the length of the wire? express your answer using two significant figures

The particle in a two-dimensional well is a useful model for the motion of electrons around the indole ring (3), the conjugated cycle found in the side chain of tryptophan. we may regard indole as a rectangle with sides of length 280 pm and 450 pm, with 10 electrons in the conjugated p system. as in case study 9.1, we assume that in the ground state of the molecule each quantized level is occupied by two electrons. (a) calculate the energy of an electron in the highest occupied level. (b) calculate the frequency of radiation that can induce a transition between the highest occupied and lowest unoccupied levels. 9.27 electrons around the porphine ring (4), the conjugated macrocycle that forms the structural basis of the heme group and the chlorophylls. we may treat the group as a circular ring of radius 440 pm, with 20 electrons in the conjugated system moving along the perimeter of the ring. as in exercise 9.26, assume that in the ground state of the molecule quantized each level is occupied by two electrons. (a) calculate the energy and angular momentum of an electron in the highest occupied level. (b) calculate the frequency of radiation that can induce a transition between the highest occupied and lowest unoccupied levels.

Simple machines can a. increase force only b. decrease force only c. increase or decrease force

Amodel rocket with a mass of 0.212 kg is launched into the air with an initial speed of 84 m/s. how much kinetic energy will the rocket have at a height of 214 m? assume there is no wind resistance. 634 j 303 j