Maria and sarah made a set of paper cup telephones. first the girls punched a hole in the bottom of each cup. then they connected the cups with a very long piece of string, knotted in the bottom of each cup. maria went down the hall to her bedroom while sarah stayed in the kitchen. when maria put the cup to her ear she could hear sarah talking to her because.

a) they were not that far from each other.
b) sound waves traveled through the string to maria’s cup.
c) sound waves traveled through the air from room to room.
d) sound waves bounced off of the walls to reach maria in the bedroom.

Akg a of 55 m at an of 11 ? . if is at 98 km/h,be ?

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.

Two technicians are discussing a resistance measurement between the can-h and can-l wires. technician a says this measurement should be done with the ignition switch in the "run" position. technician b states that a measurement of 0 ohms indicates an open in the network. which technician is correct?