Solved: Let us try to estimate the maximum static

Chapter , Problem 96

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Let us try to estimate the maximum static electricitycharge that might result during each walking step across aninsulating floor. Assume the sole of a persons shoe has areaA ~ 150 cm2, and when the foot is lifted from the groundduring each step, the sole acquires an excess charge Q fromrubbing contact with the floor, (a) Model the sole as a planeconducting surface with Q uniformly distributed across it as thefoot is lifted from the ground. If the dielectric strength of theair between the sole and floor as the foot is lifted isE$ = 3 X 106N/C, determine Qmax, the maximum possibleexcess charge that can be transferred to the sole during eachstep. (b) Modeling a person as an isolated conducting sphere ofradius r 1 m, estimate a persons capacitance, (c) Afterlifting the foot from the floor, assume the excess charge Qquickly redistributes itself over the entire surface area of theperson. Estimate the maximum potential difference that theperson can develop with respect to the floor.