Estimate the average speed, in m/s, with which tge hair on your head grows. make this estimate from your own experience nothing, for instance, how often you cut your hair and how much you trim. express your result in scientific notation.

My estimate is 1/2 inch per week.

     (0.5 inch/wk) x (1 wk / 7 da) x (1 da / 86,400 sec) x (1 meter / 39.37 inches)

 =     (0.5 x 1 x 1 x 1) / (7 x 86,400 x 39.37)        meter/second

 =               1 / 47,621,952  meter/second 

 =                  0.0000000209987...  m/s

 =                2.1 x 10⁻⁸  meter/second

 =                2.1 x 10⁻⁵ mm/sec

 =                0.000021 millimeter per second  (rounded)