Sailors traditionally measure speed in knots or nautical mil

Sailors traditionally measure speed in knots, or nautical miles per hour. A nautical mile is based on the circumference of the Earth, and 1 nautical mile = 1.15 mile. a. If a ship is (travelling at 15 nautical miles per hour, how fast is it going in miles per hour? b. What about in feet per second? (1 mile = 5, 280 feet)

Solution

a.

1 nautical mile=1.15 miles

So, 15 nautical miles per hour=15*1.15 miles per hour=17.25 miles per hour

b.

1 mile =5280 feet

1 hour=3600 s

So, 17.25 miles per hour=17.25*5280/3600 feet /second= 25.3 feet per second