13. a submarine was cruising at a depth of 153 m. it then rose at 4.5 m/min for 15 min. a) what was the…

13. a submarine was cruising at a depth of 153 m. it then rose at 4.5 m/min for 15 min. a) what was the submarine’s depth at the end of this rise? b) if the submarine continues to rise at the same rate, how much longer will it take to reach the surface?

13. a submarine was cruising at a depth of 153 m. it then rose at 4.5 m/min for 15 min. a) what was the submarine’s depth at the end of this rise? b) if the submarine continues to rise at the same rate, how much longer will it take to reach the surface?

Answer

Explanation:

Step1: Calculate the distance risen

The submarine rises at a rate of 4.5 m/min for 15 min. Using the formula distance = rate×time, we have $d = 4.5\times15$. $d=4.5\times15 = 67.5$ m

Step2: Calculate the new depth

The initial depth is 153 m. Subtract the distance risen from the initial depth. Let the new - depth be $D$. Then $D=153 - 67.5$. $D = 153-67.5=85.5$ m

Step3: Calculate the time to reach the surface

The remaining distance to the surface is 85.5 m and the rate is 4.5 m/min. Using the formula time = distance/rate, let the time be $t$. Then $t=\frac{85.5}{4.5}$. $t=\frac{85.5}{4.5}=19$ min

Answer:

a) 85.5 m b) 19 min