Originally Posted by
Wizofoz
Ian,
You've made the same fundamental error- and you've been arrogant with it.
Before saying someone has forgotten basic physics, you'd best learn some yourself.
The earth is not a privileged frame of reference and no, no value HAS to be calculated in reference to it. All calculations of velocity, acceleration and therefore momentum and kinetic energy work in any frame of reference- as long as you STAY in one frame of reference.
Momentum is not related to groundspeed. It is related of whatever frame of reference you choose to calculate in.That is implicit in Newtons first law of motion,
If you read the post from A-Squared where he suggested I go to a friendly university physicist - taking about 4 sentences - you will see why I said what I did.
Momentum is not related to groundspeed. It is related of whatever frame of reference you choose to calculate in.That is implicit in Newtons first law of motion
I choose the ground as my frame of reference then. Aircraft stationary in my frame of reference and in 30 seconds accelerates to 120kts. Or alternately is traveling at 120Kts and in 30 seconds becomes stationary