A somewhat simplified model of the body is sometimes used in estimating currents

Question

A somewhat simplified model of the body is sometimes used in estimating currents received by the body during electrical accidents. We'll be referring to the figure below in the following problem.

Assume the following resistances:

A worker accidentally grabs a 170-Volt power line with both hands and stands in a puddle, effectively grounding both feet. What is the equivalent resistance of the body in this case?

What is the total current passing through the torso?

Assuming ground to be 0V, what is the voltage at the neck (the point where R1,R2 and R3 join)?

The person manages to let go of the wire with the left hand. What happens to the following quantities? (Increase, decrease, or stay the same?)

IncreaseStays SameDecrease The equivalent resistance used to calculate the total current.
IncreaseStays SameDecrease Resistance of the left leg.
IncreaseStays SameDecrease The Voltage at the hips (the point where R3, R4 and R5 join).
IncreaseStays SameDecrease The current through the torso.

Right Arm R1 575 ? Left Arm R2 575 ? Torso R3 140 ? Right Leg R4 425 ? Left Leg R5 425 ?

A somewhat simplified model of the body is sometimes used in estimating currents received by the body during electrical accidents. We'll be referring to the figure below in the following problem.

Explanation / Answer

1 and 2 are in parallel

as are 4 and 5

R total = 575/2 + 140 + 425/2= 640 ohms

I = V/R = 170/640=0.266 A

V at neck = 170 - 575/2 * 0.266=93.5 V

equivalent resistance increases

resistance of left leg stays the same

voltage at hips decreases

current decreases

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