Two identical objects, A and B, move along straight, parallel, horizontal tracks. The graph above represents the velocity as a function of time for the two objects. (a) Indicate which of the two objects, if either, has a decreasing speed during the time interval shown. If neither object has a decreasing speed, indicate this explicitly. Briefly explain your answer.
(b) Indicate at approximately which time or times, if any, the objects are moving at the same speed. If the objects are never moving with the same speed during the interval shown, indicate this explicitly. Briefly explain your answer.

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.

Which types of electromagnetic waves have higher frequencies than the waves that make up ultraviolet light? check all that apply. radio waves infrared light microwaves gamma rays visible light x-rays

Chemical energy is a form of energy. a. heat b. kinetic c. potential d. electromagnetic