Question

A severe storm on January 10, 1992, caused a cargo ship near the Aleutian Islands to spill 29,000 rubber ducks and other bath toys into the ocean. Ten months later hundreds of rubber ducks began to appear along the shoreline near Sitka, Alaska, roughly 1600 miles away.
What was the approximate average speed of the ocean current that carried the ducks to shore in m/s and in mi/h? (Rubber ducks from the same spill began to appear on the coast of Maine in July 2003.)

Answer 1

The distance that the rubber ducks traveled = 1600 miles.
The time taken to travel this distance = 10 months.

By definition, the approximate average speed of the ocean is
v = (1600 miles)/(10 months)

Note that
1 mile = 1609 m 
10 months = (10 months)*(30 days/month) *(24 hours/day)
                  = 7200 hours (approx.)
                  = 7200*3600 = 2.592 x 10⁷ s

Therefore
$v = \frac{(1600 \, m)*(1609 \, \frac{m}{mi}) }{(10 \, months)*(2.592 \times 10^{7} \, \frac{s}{10 \, months}) } = 0.0993 \, \frac{m}{s}$

Also,
$v = \frac{1600 \, m}{7200 \, h} =0.222 \, \frac{mi}{h}$

Answer:
The average velocity is approximately 0.1 m/s, or 0.222 m/h.