Q5 of 32 Page 242

A ship can cover a certain distance in 10 hours at a speed of 16 nautical miles per hour. By how much should its speed be increased so that it takes only 8 hours to cover the same distance? (A nautical mile in a unit of measurement used at sea distance or sea water i.e. 1852 meters).

Given: Speed in 10 hours = 16 nautical miles per hour

To find: Increase in speed required if the ship has to cover the same distance in 8 hours.


Formula:


Substituting x1 = 10, y1 = 16 x2 = 8 in the formula,



Gives y2 = 20 nautical miles per hour


Change in speed = Final Speed – Initial Speed


20-16 = 4 nautical miles per hour.


∴ The speed must be increased by 4 nautical miles per hour for the ship to cover the same distance in 8 hours.


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