An all female guitar septet is getting ready to go on stage. the lead guitarist, kira, who is always in tune, plucks her low e string and the other six members, sequentially, do the same. each member records the initial beat frequency between her low e string and kira's low e string.

to tune an instrument using beats, more information than just the beat frequency is needed. in addition to recording the initial beat frequency , each member, except diane, also records the change in the frequency (increase or decrease) when they increase the tension in their low e string.

rank each member on the basis of the initial frequency of their low e string.
rank from largest to smallest. to rank items as equivalent, overlap them.

a. aiko=3hz, fbeat increases
b. chandra=1hz fbeat decreases
c. evita=5hz fbeat decreases.
d. freja=3hz fbeat decreases.
e. buffy=4hz fbeat increases.

Chapter 23, problem 075 the figure shows a geiger counter, a device used to detect ionizing radiation (radiation that causes ionization of atoms). the counter consists of a thin, positively charged central wire surrounded by a concentric, circular, conducting cylindrical shell with an equal negative charge. thus, a strong radial electric field is set up inside the shell. the shell contains a low-pressure inert gas. a particle of radiation entering the device through the shell wall ionizes a few of the gas atoms. the resulting free electrons (e) are drawn to the positive wire. however, the electric field is so intense that, between collisions with gas atoms, the free electrons gain energy sufficient to ionize these atoms also. more free electrons are thereby created, and the process is repeated until the electrons reach the wire. the resulting "avalanche" of electrons is collected by the wire, generating a signal that is used to record the passage of the original particle of radiation. suppose the radius of the central wire is 24 âµm, the inner radius of the shell 2.3 cm, and the length of the shell 14 cm. if the electric field at the shell's inner wall is 2.8 ă— 104 n/c, what is the total positive charge on the central wire?