Quote:
Originally Posted by Abwehr
Equations: ...
If x = 48 ft = 14.6 m and t = 6s, then
14.6 = .5*a*36
a = 0.811 m/s^2
Plugging back into our first equation...
0.811 m/s^2 = u*7.94 m/s^2
u = .102 (at least)
Possible Conclusion 1: If we are to believe Dave's claims about traversing the field forward and back in about 12 seconds, then the published FIRST figures must be wrong.
Possible Conclusion 2: FIRST measured their CoF on a worn floor, while Dave drove on a new floor.
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Lovely math.
Your model is driving full speed end to end, without even a turnaround and decel. Top speed before hitting the wall is 0.811m/s^2*6s = 4.866m/s.
Does the stock transmission setup support that top speed?
To get to half-field in 3 seconds with this same accel, your initial velocity has to be 1.21m/s, or about 1.5s worth of accel. To summarize: u=0.102 also supports a model of accellerating to midfield, instant reverse accel, and bounce off walls perfectly elasticly at a bounce speed of 1.2m/s. This model drops the top speed to 3.64m/s by raising the average speed.
I wonder how it works out if you assume a lesser elasticity, like 80%, and a late non-midpoint reversal. ie faster crash, slower bounceback
A video of someone doing laps with trailer on a real field would be awesome.
Mass of MoonRock payload is assumed to be neglegible.
Re COF measurements: Is there a difference between static friction with a rolling wheel, vs static friction on a fixed wheel? It sounds like most people are measuring with a drag sled fixed wheel.