Combining Resistors in Series & Parallel Video Lessons

Concept

# Problem: It's possible to estimate the percentage of fat in the body by measuring the resistance of the upper leg rather than the upper arm; the calculation is similar. A person's leg measures 40 cm between the knee and the hip, with an average leg diameter (ignoring bone and other poorly conducting tissue) of 12 cm. A potential difference of 0.78V causes a current of 1.6 mA. What are the fractions of muscle and fat in the leg? Express your answer using two significant figures separated by a comma.

###### FREE Expert Solution

The leg's resistance is found by:

$\overline{)\frac{\mathbf{1}}{{\mathbf{R}}_{\mathbf{r}}}{\mathbf{=}}\frac{\mathbf{1}}{\mathbf{V}}}$

The fraction of fat, ffat

84% (276 ratings)
###### Problem Details

It's possible to estimate the percentage of fat in the body by measuring the resistance of the upper leg rather than the upper arm; the calculation is similar. A person's leg measures 40 cm between the knee and the hip, with an average leg diameter (ignoring bone and other poorly conducting tissue) of 12 cm. A potential difference of 0.78V causes a current of 1.6 mA. What are the fractions of muscle and fat in the leg? Express your answer using two significant figures separated by a comma.