Final answer:
To calculate the time for the fish and submarine to be 15 miles apart, their speeds are added since they travel in opposite directions to get a combined speed of 120 mph. Thus, it takes 0.125 hours (7.5 minutes), but the closest provided option is A) 0.5 hours, which suggests a potential issue with the options.
Step-by-step explanation:
The subject of your question is Mathematics, specifically dealing with relative motion and rate problems. To find out how long it will take before the fish and the submarine are 15 miles apart when the fish is swimming 70 miles per hour and the submarine is moving 50 miles per hour in opposite directions, we add their speeds together since they are moving away from each other. The combined speed is 70 mph + 50 mph = 120 miles per hour. To find the time, we use the formula Time = Distance / Speed. Plugging in the numbers, we get Time = 15 miles / 120 miles per hour = 0.125 hours. To convert this into minutes, we multiply by 60 (since one hour has 60 minutes) and this gives us 7.5 minutes. However, since the options provided are in hours and the closest option to 0.125 hours is A) 0.5 hours, it seems there might be an error in the options provided as none of them correctly match the calculated time of 0.125 hours (7.5 minutes).
To find the time it takes for the fish and the submarine to be 15 miles apart, we can use the relative speed of the fish and the submarine:
Relative speed = Speed of fish + Speed of submarine
Relative speed = 70 mph + 50 mph = 120 mph
Now, we can use the formula:
Distance = Speed × Time
Time = Distance / Speed
Time = 15 miles / 120 mph
Time ≈ 0.125 hours
So, none of the provided options (A, B, C, D) exactly match the calculated time. However, the closest match is:
A) 0.5 hours
It's worth noting that the calculated time is approximately 0.125 hours or 7.5 minutes, which is closer to option A than the other options.