Suppose an experiment is designed to test the durability of batteries in different conditions. all of the batteries tested are double-a (aa) brand x. all sets of batteries are preconditioned in different environmental conditions for exactly 168 hours (1 week).
set 1: 0°c (freezing point of water)
set 2: 24°c (approximately room temperature)
set 3: 37°c (approximately body temperature)
the batteries are then continuously used to power identical mechanical drummer toys. as long as the toy keeps drumming the battery is considered functional. the drumming time for each toy is measured as an indication of battery durability.
in this experiment, which condition is not controlled?
brand of batteries
type of battery (battery size)
temperature
test for durability

Matt is driving down 7th street. he drives 150 meters in 18 sec. assuming he doesn’t slow down or speed up, what is his speed?

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.

Acompound machine is also called a machine. a. force b. simple c. complex d. directional