Author Topic: Kinetic Energy Mode  (Read 2836 times)

Offline Numsgil

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Kinetic Energy Mode
« on: June 05, 2005, 09:46:36 AM »
The equation for "KE Mode" works like this:

cost = (.5 * mass * deltavmagnitude) / 4

where deltavmagnitude = final velocity magnitude^2 - initial velocity magnitude^2

The major problem I have with this equation conceptually is it's clear bias towards a set frame of reference (namely, the observer).

I don't think you can calculate the force needed to accelerate an already moving object like this because the object may or may not be moving from any given frame of reference.

Assuming the object is alone in the universe (as indeed the equation supposes, since it includes no other forces) it has no way of determining how fast it's moving, or if it's moving at all.  It's only when we take into account the velocity relative to the big blue screen that this makes any sense at all.  And then you have drag and friction which sap the speed, not the velocity relative to it.

So the reason a car takes increasingly more Horsepower to accelerate faster and faster isn't because it's going faster and faster.  If a car could theoretically work in an empty vacuum, it can continue accelerating at a constant rate given a constant energy input.  The only caveat is that as it approaches the speed of light, relativity will begin to warp its sense of distance and time when compared to our "resting" frame of reference.

Back on topic, it's drag and friction and other resistive forces that eventually will lower a car's acceleration with constant horsepower to 0.

So once we come up with a realistic drag control setting, I see no reason to keep KE mode or attempt to fix it.  Trying to 100 .up store will eventually reach a constant speed (if the slider is set right this can be below the max speed) where a constant 100 nrg is required to maintain said speed.

Thus moving at lower speeds is better because the resistive forces are disproportionately lower.

I think that's more realistic, solves the same problems, and works all around better.
« Last Edit: June 05, 2005, 09:49:24 AM by Numsgil »

Offline PurpleYouko

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Kinetic Energy Mode
« Reply #1 on: June 05, 2005, 11:16:27 AM »
Yup definitely more realistic.

In fact with the recent improvements to movement physics, the distinction between normal and KE mode has been getting steadily more difficult to grasp.

Right now it is simply the difference between Kinetic energy (1/2 MV^2) and momentum (MV). It really doesn't make that much difference any more.

Once drag in introduced this distinction will pretty much disappear so there ain't much point keeping the option.

Besides this, nobody except Shvarz ever really uses it anyway.  :D
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Offline Numsgil

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Kinetic Energy Mode
« Reply #2 on: June 05, 2005, 10:42:06 PM »
Alot of this stuff gives me a headache, but I'm busy at work figuring out how drag can be done.

Turns out there's quite a few forces at work for an object moving through a viscous fluid.  Such a pain.

Offline shvarz

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Kinetic Energy Mode
« Reply #3 on: June 06, 2005, 01:48:01 AM »
Quote
Besides this, nobody except Shvarz ever really uses it anyway

Well, I think this is good enough reason already!

 :rolleyes:
"Never underestimate the power of stupid things in big numbers" - Serious Sam