KSP Stock Weapon Physics: Is KE=M*DV more important than Velocity alone?

[RedPine]

Early in my attempts to make good Stock weapons, I've come across some bizarre irregularities regarding what weapons can destroy which objects. First I'll introduce the craft I used, all of which have projectiles with a crash tolerance of 80m/s.

This is the Yelll Mk I Broadside. Each projectile travels at 59m/s and spins rapidly.

This is the Red Mk II Sniper, aimed manually with a KerbPro camera from HullcamVDS. Each projectile travels at 89m/s and spins slowly.

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First off, you would think high crash tolerance and mass make a part sturdier, right? WRONG!

Target specs:

Nuclear Engine CT12,m2.25t Destroyable by Broadside and Sniper (High crash tolerance and weight, but is easy to destroy?!)

Dry Fuel Tank CT06,m1.00t Destroyable by Broadside Only (Low crash tolerance and weight, but is hard to destroy?!)

You would think the Sniper would have a more powerful projectile than the Broadside due to higher speed, but the reverse is true! The Broadside can destroy fuel tanks and engines, but the Sniper can only destroy engines but not empty fuel tanks!

The projectile specs:

Broadside RV59m/s,m0.57t,DV59m/s (Low DV, Low Speed, High Mass, powerful weapon?!)

Sniper RV89m/s,m0.13t,DV94m/s (High DV, High Speed, Low Mass, weak weapon?!)

This doesn't make sense. Bullets are light and fast, and they work in real life! But KSP is a physics simulator, so maybe Kinetic Energy is more important than just Velocity. KE=1/2*M*V^2. I don't know if it matters if a projectile is spinning or not, but relative velocity and DV were close enough that it doesn't matter for the projectiles I used.

Projectile specs (Kinetic Energy = 1/2*Mass*Velocity):

Broadside 0.5*Mass*Relative Velocity^2=992 (If KE is high, strong weapon)

Sniper 0.5*Mass*Relative Velocity^2=514 (If KE is low, weak weapon)

Hmm, the more effective weapon had a high KE. I'll need more testing to prove my theory, but I think KE is more important to KSP collisions than Crash Tolerance, or Speed and Mass alone! Future tests will confirm whether a fast spinning projectile (High M*DV, Low M*V) is better than a non spinning projectile (Low M*DV, High M*V). Let me know if you have any suggestions or information for me!

Key: RV = Relative Velocity in m/s. CT = Crash Tolerance in m/s. M = Mass in Tons. DV = Delta Velocity in m/s.

Edited February 8, 2015 by RedPine
Error in formula

[Vanamonde]

How-to kind of discussion moved to the how-to subforum. Carry on.

[Tank Buddy]

Just to let you know KE = .5 * M * V^2. Also, I would think parts in KSP break purely because they experience hitting a surface (or being hit) at greater than the crash tolerance velocity, so KE may not matter.

[RedPine]

Sorry about the KE mistake, I should have googled it. Whoops. I've edited the OP. That aside, you don't seem to have understood my post - crash tolerance is NOT what we think it is. Both projectiles had crash tolerances of 80m/s and traveled faster than 50m/s towards targets with crash tolerances of 12m/s or less, and yet it most cases the projectiles were destroyed, not the targets. Clearly mass or some other unknown factor is at work in determining whether the target or the projectile is destroyed.