A nerve signal is transmitted through a neuron when an excess Na+ inos suddenly enters the axon, along cylindrical part of the neuron. Axons are approximately 10.0 micrometer in diameter, and measurements show that about 5.6×10^11 Na+ ions per meter ( each of charge e+)enter during this process. Although the axon is a long cylinder, the charge doesn’t all enter everywhere at the same time. A plausible model would be a series if point charges moving along the axon. Let us look at a 0.10-mm length of the axon and model it as a point of charge.

(a) If the charge that enters each meter of the axon gets distributed uniformly along it, how many coulombs of charge enter a 0.10-mm length of the axon?
(b) What electric field ( magnitude and direction) does the sudden influx of charge produce at the surface of the body if the axon is 5.00 cm below the skin?
(c) Certain sharks can respond to electric fields as weak as 1.0 microN/C. how far from this segment of axon could a shark be and still detect its electric field?