HW1.9 - Estimates and Order-of-Magnitude Calculations Note: In developing answers to the problems in this section, you should state your important assumptions, including the numerical values assigned to parameters used in the solution. 1. Estimate the number of steps you would have to take to walk a distance equal to the circumference of the Earth. 2. Treat a cell in a human as a sphere of radius 1.0m. (a) Determine the volume of a cell. (b) Estimate the volume of your body. (c) Estimate the number of cells in your body