Post #36269 by onepoorguy on the US Policy board

Halls of Shrewd'm / US Policy ❤

Unthreaded | Threaded | Whole Thread (47)

Post New | Post Reply | Report Post | Recommend It!

No. of Recommendations: 4

That's a torpedo, not a manned object.

Also, "super-cavitating" is loud. Very loud. Which would be detected by (among other things) SOSUS.

The fasted experimental sub was something above 50mph. The Russian Alfa (the fastest sub that saw actual service) was 47mph.

Drag (friction) goes as the square the velocity in a fluid. So you can optimize the drag coefficient (by streamlining the object per the laws of physics), but since you can never get it to zero, the faster you go, the drag is exponential.

A bullet (very streamlined, though not optimized since the back of the bullet is flat, not tapered) will lose all of it's energy in about a meter of water.

Post New | Post Reply | Report Post | Recommend It!

Print the post

Unthreaded | Threaded | Whole Thread (47)

Prev | Next

Announcements

US Policy FAQ

Contact Shrewd'm
Contact the developer of these message boards.

A community forum supporting civilized, and highly helpful, self-educating investors that come together for Shrewdness and merry spirits. These message boards closely follow the look and feel of the old message boards at boards.fool.com prior to the boards redirected to discussion.fool.com. Shrewd'm is not affiliated with the comprehensive and excellent investment website, The Motley Fool (TMF), in any way. The Shrewd commmunity here has owed, and continues to owe, gratitude to The Motley Fool for nurturing a culture of jovial irreverence towards Wall St, and that tradition will continue here.