Chapter 7, Problem 56AP

Keratinocytes are the most common cells in the skin’s outer layer. As these approximately circular cells migrate across a wound during the healing process, they roll in a way that reduces the frictional forces impeding their motion. (a) Given a cell body diameter of 1.00 × 10⁻⁵ m (10 μm), what minimum angular speed would be required to produce the observed linear speed of 1.67 × 10⁻⁷ m/s (10 μm/min)? (b) How many complete revolutions would be required for the cell to roll a distance of 5.00 × 10⁻³ m? (Because of slipping as the cells roll, averages of observed angular speeds and the number of complete revolutions are about three times these minimum values.)