Question

One scuba diver descends from 135 feet below sea level at a rate of 1 foot per 2 seconds. Along the same path (but in the opposite direction) another scuba diver descends from sea level at 4 feet per second.

In how many seconds will the scuba divers be at the same place?

Answer 1

In 30 seconds.

Explanation:

What we need to calculate is the time at which they would both meet.

We should note they are coming from opposite directions, hence, their meeting distance most both add up to be 135 feet.

Now,the first scuba diver moves at a speed of 1 foot per 2 seconds, hence, his speed per second is 0.5ft/s.

To get our answer, we need to share the total distance I.e 135 into ratio of their speeds.

Now total speed = 4 + 0.5 = 4.5ft/s

We now divide this into distances.

We place 0.5/4.5 × 135 = 15ft

We place 4/4.5 × 135 = 120ft

The time taken for the first diver to reach 15ft is 15/0.5 = 30 seconds

The time taken for the opposite diver to reach 120ft is 120/4 = 30 seconds.