"Marine Carrier"

SWM wrote:

Relax wrote:Elementary math time:

1 - -1 = what again?

dV
65 - -65 = 130

130-0 = 130

Kinetic Energy = 1/2m(dV^2)

That v in kinetic energy equation is not derived from a static equation. That is the simplified version with the calculus removed.

http://www2.physics.umd.edu/~alaporta/PHYS171_f12/lectures/kinetic_energy.pdf

EDIT:

Graph it: Draw a positive squared function above the positive x axis and then draw the identical negative function mirrored on the positive x axis. What is the area between the two curves?

Draw a positive squared function 2x greater than the single squared function on the positive x axis. What is the area under the curve?

The areas are identical.

No, I'm afraid that you are wrong. There is a difference between these two situations:
one vehicle (1kg) traveling at 20 m/s, colliding with a stationary vehicle (1 kg), and traveling at zero afterwards. Total kinetic energy before: 400 joules. Total kinetic energy afterward: 0 joules. Difference in kinetic energy (i.e. the energy consumed in damaging the vehicle and contents): 400 joules.

2 vehicles (1 kg each) traveling toward each other, each at 10 m/s, colliding with each other, and traveling at zero afterward. Total kinetic energy before: 200 joules. Total kinetic energy afterward: 0 joules. Difference in kinetic energy: 200 joules.

You are assuming that the second situation can be viewed from the frame of reference of the second vehicle. So let's take a closer look at that. Vehicle 1 is traveling toward vehicle 2 at 20 m/s. It collides. Afterward, vehicles 1 and two are crumpled together, and traveling at 10 m/s!. The frame of reference is not glued to vehicle 2. In that frame of reference, the merged vehicles are moving after the collision! Total kinetic energy before: 400 joules. Total kinetic energy after: 200 joules. Difference in kinetic energy: 200 joules. The same result as we got in the other frame of reference.

No matter what frame of reference you use, the two situations are not the same. A collision involving two vehicles at equal speeds head on gives half as much damaging energy as a collision involving one vehicle traveling twice as fast.

I'd taken "stationary object" to mean "(effectively) immovable" object - not "object of the same mass but at 0 m/s"

Colliding with a thick reinforced concrete wall is different from colliding with a stopped vehicle. You and the wall aren't going to be moving together at 10 m/s


I thought two car, of equal mass, slamming directly head on into each other at the same speed, is roughly equivalent to each running into an (effectively) immovable barrier. (But I admit to having not done the math tonight)

Jonathan_S wrote:

SWM wrote:No, I'm afraid that you are wrong. There is a difference between these two situations:
one vehicle (1kg) traveling at 20 m/s, colliding with a stationary vehicle (1 kg), and traveling at zero afterwards. Total kinetic energy before: 400 joules. Total kinetic energy afterward: 0 joules. Difference in kinetic energy (i.e. the energy consumed in damaging the vehicle and contents): 400 joules.

2 vehicles (1 kg each) traveling toward each other, each at 10 m/s, colliding with each other, and traveling at zero afterward. Total kinetic energy before: 200 joules. Total kinetic energy afterward: 0 joules. Difference in kinetic energy: 200 joules.

You are assuming that the second situation can be viewed from the frame of reference of the second vehicle. So let's take a closer look at that. Vehicle 1 is traveling toward vehicle 2 at 20 m/s. It collides. Afterward, vehicles 1 and two are crumpled together, and traveling at 10 m/s!. The frame of reference is not glued to vehicle 2. In that frame of reference, the merged vehicles are moving after the collision! Total kinetic energy before: 400 joules. Total kinetic energy after: 200 joules. Difference in kinetic energy: 200 joules. The same result as we got in the other frame of reference.

No matter what frame of reference you use, the two situations are not the same. A collision involving two vehicles at equal speeds head on gives half as much damaging energy as a collision involving one vehicle traveling twice as fast.

I'd taken "stationary object" to mean "(effectively) immovable" object - not "object of the same mass but at 0 m/s"

Colliding with a thick reinforced concrete wall is different from colliding with a stopped vehicle. You and the wall aren't going to be moving together at 10 m/s


I thought two car, of equal mass, slamming directly head on into each other at the same speed, is roughly equivalent to each running into an (effectively) immovable barrier. (But I admit to having not done the math tonight)

Yes, you're right, case 1 should really be read as car colliding with wall, not another car. Otherwise you don't get the zero velocity afterward.

SWM wrote:

Relax wrote:Elementary math time:

1 - -1 = what again?

No, I'm afraid that you are wrong. There is a difference between these two situations:
one vehicle (1kg) traveling at 20 m/s, colliding with a stationary vehicle (1 kg), and traveling at zero afterwards. Total kinetic energy before: 400 joules. Total kinetic energy afterward: 0 jou

Yea, I only did one FoR.

Screwed the pooch.

Added extra screwup on the graph as I did a m/V graph instead of m/KE graph...

Figured it out at 2am last night as I couldn't get to sleep laying in bed with a bum sore shoulder from cutting firewood.

Relax wrote:Yea, I only did one FoR.

Screwed the pooch.

Added extra screwup on the graph as I did a m/V graph instead of m/KE graph...

Figured it out at 2am last night as I couldn't get to sleep laying in bed with a bum sore shoulder from cutting firewood.

Don't you hate it when you finally figure out mistakes at that hour!

SWM wrote:

Relax wrote:Yea, I only did one FoR.

Screwed the pooch.

Added extra screwup on the graph as I did a m/V graph instead of m/KE graph...

Figured it out at 2am last night as I couldn't get to sleep laying in bed with a bum sore shoulder from cutting firewood.

Don't you hate it when you finally figure out mistakes at that hour!

At least as much fun as staring at a programming problem for 5 hours, having someone walk up behind you, point at a line on the screen, and ask "Why did you do that?", and realizing "OMG, that's what's wrong" . Leads to considerable dents in the forehead from the keyboard.

SWM wrote:

Relax wrote:Yea, I only did one FoR.

Screwed the pooch.

Added extra screwup on the graph as I did a m/V graph instead of m/KE graph...

Figured it out at 2am last night as I couldn't get to sleep laying in bed with a bum sore shoulder from cutting firewood.

Don't you hate it when you finally figure out mistakes at that hour!

The hour is fine. Actually when I do some of my best thinking. Now laying flat splat in the mud puddle on the other hand...

Kammerling?

One thing I never could figure out was why there is no Marines space?

The crews are smaller but the Marines are not part of the crew in as much as being just carried passengers who do the Marines thing. It isn't like they are Marines but are also gunners or CM or Engineers as well as being Marines. The ships are automated and have less crew members but why wouldn't they have any Marines it isn't like the ships are tiny small, just the opposite they are much larger.

A Talisman CL crew 1200 is 66% percent the size of a Roland. Yet the Roland with only 65-67? crew can't find room for 100 Marines. This might be a problem that Would be over looked in a preliminary design Phase but would be caught by anyone who has ever designed a Ship. I could see Grayson making this mistake with their first ship design, the Manty's laughing over their Old Tillman it didn't have any Marine support, there are 65 of them all at their stations trying to figure out who they can send over to capture the LAC but nobody is available. HAHAHA.

Come on.

Honor Among Enemies: Chapter 6 wrote:The Royal Manticoran Marines were specialists who held shipboard duty assignments as well as providing boarding parties and emergency ground combat components. Heavy planetary combat was the role of the Royal Army, which, undistracted by the need to master shipboard systems, could concentrate solely on planetary combat hardware and techniques.

Honor Among Enemies: Chapter 11 wrote:Like the Grayson Navy, but unlike the RMN, the IAN's Marines were Army units assigned to shipboard duty. Andermani ships also carried less of them, since their sole function was to provide a ground combat and boarding force, but their drill was as sharp as anything Honor's own Marines might have turned out, and they looked both competent and dangerous, even in dress uniform.

Honor Among Enemies: Chapter 23 wrote:Marines might man weapon stations at GQ, but they had their own mess, their own berths, their own exercise areas, their own officers and noncoms. They had different traditions and rituals which didn't make a lot of sense to a naval rating, and they seemed perfectly content to keep it that way.

It's interesting how the Marines in a normal warship have normal shipboard jobs beyond just being ready to provide boarding or away parties.

House of Steel goes into a bit of the downsides when they temporarily got merged into the army and didn't get the training in "the shipboard duties like damage control and weapons crews which had always been part of the traditional Marine role." I guess that's a reflection back to the age of sail when a ship's marines usual did have a few guns they'd man during ship-to-ship combat (in addition to acting as sharpshooters, and of course making up a significant part of the firepower in any boarding action, or landing party)

Though I assume things are different in a Broadsword or Kammerling class ship; way too many Marines for each to have a real duty station.

Jonathan_S wrote:]It's interesting how the Marines in a normal warship have normal shipboard jobs beyond just being ready to provide boarding or away parties.

House of Steel goes into a bit of the downsides when they temporarily got merged into the army and didn't get the training in "the shipboard duties like damage control and weapons crews which had always been part of the traditional Marine role." I guess that's a reflection back to the age of sail when a ship's marines usual did have a few guns they'd man during ship-to-ship combat (in addition to acting as sharpshooters, and of course making up a significant part of the firepower in any boarding action, or landing party)

Though I assume things are different in a Broadsword or Kammerling class ship; way too many Marines for each to have a real duty station.

It's a tricky thing that each of these navies has struggled with over time. On the one hand, having someone aboard who isn't needed under predictable, important circumstances is a luxury for a warship. On the other, there will be those occasions for boarding actions and landing parties.

The classic RMN approach has been to have socially separate Marines as integral parts of certain parts of the crew. They do two things (at a high level of description): they work parts of the ship, they also do more personal mayhem and threats of mayhem. Keeping people trained for that has got to be tricky. They're like pulp fiction heroes who are doctors and lawyers.

The classic GSN and IAN approach has been to have people aboard who do just do the personal mayhem and are not otherwise employed aboard ship. Training's a lot easier to get and maintain, but you've got to be desperately tempted to get these bodies out of the ship when you don't have that mayhem to do.

A third approach - the RMN seems to be finding itself doing it as an expedient with the small-crew modern ships - is Naval Rating as Emergency Backup Marine: the mirror image of the classic RMN approach, the Marine as Emergency Backup Rating.

The demanding cross-training is, well, demanding, but I figure the RMN is going to stay more inclined to do it than to keep people they cannot keep regularly employed in their precious crew cubage. Hopefully they'll shake down into some approach that is a bit less making it back up as they go along.

Relax wrote:Yea, I only did one FoR.

Screwed the pooch.

Added extra screwup on the graph as I did a m/V graph instead of m/KE graph...

Figured it out at 2am last night as I couldn't get to sleep laying in bed with a bum sore shoulder from cutting firewood.

SWM wrote:Don't you hate it when you finally figure out mistakes at that hour!

fallsfromtrees wrote:At least as much fun as staring at a programming problem for 5 hours, having someone walk up behind you, point at a line on the screen, and ask "Why did you do that?", and realizing "OMG, that's what's wrong" . Leads to considerable dents in the forehead from the keyboard.

That last one is part of Murphy's Law of Computation, SNAFU Equations (JB's Scholastic Laws): "In any human endeavor, once you've exhausted all possibilities and fail, there will be one solution, simple and obvious, highly visible to everyone else."

Everyone who has ever programmed a computer has personally experienced this law in action.