Final answer:
The student's question concerning the length of heavyweight torpedoes, given in diameter, is a conversion problem typically seen in high school level mathematics.
Step-by-step explanation:
The student asked about heavyweight torpedoes which are typically 533mm in diameter, and they are seeking an approximation of how many feet long these torpedoes are.
Although additional context may provide a more precise length, one can note that large naval torpedoes are often around 20 feet in length.
Since the question's primary aim seems to be around converting from one set of units to another or understanding sizes, it is a mathematical question.
Most heavyweight torpedoes are typically 533mm (21in) in diameter and are usually around 9 to 10 meters long. To convert this length into feet, we can use the conversion factor that 1 meter is approximately 3.28 feet. So, a typical heavyweight torpedo is nearly 30 to 33 feet long.