Respuesta :

Part A

We were told that the submarine descends 480 feet in 24 seconds. Since it is descending,the distance would be negative. Let x represent the descent in 1 second. Thus, the expressions would be

- 480 = 24

x = 1

By cross multiplying, we have

x * 24 = 480 * 1

24x = - 480

x = - 480/24

Thus, the correct option is the thrd one

Part B

Let the constant rate be x ft/sec

This means that after 8 seconds, the elevation change would be

8 * x

= 8 feet