Question

A submarine submerges at the rate of 5 m/min. If it descends from 20 m above the sea level, how long will it take to reach 250 m below sea level?

Answer 1

Given,
Initial position = 20 m (above sea level)
Final position = 250 m (below sea level)
Total depth it submerged = (250+20) = 270 m
Thus, the submarine travelled 270 m below sea level.
(1 mark)

Rate of submergence = 5 m per minute
Time taken to submerge 1 meter = $\frac{1}{5}$ minutes
Time taken to submerge 270 m = 270 x $\frac{1}{5}$ minutes =54 minutes

Hence, the submarine will reach 250 m below sea level in 54 minutes.
(1 mark)