Originally posted by Racer X 69 No offense taken.

But.

Will a 645Z hit 150mph + on the straights?

wellll, let's see

Terminal velocity = Sqrt((2 * mass * g) / (air density * projected area * drag coeff))

Mass = 1.5kg (w/ batteries)

g =9.8

air density at +25*C (there's no point to experiment in the cold) - about 1.18kg/m3, humidity and change of t* depending on height are not taken into account

dimensions: 0.156 * 0.117 * 0.123m

for our purposes, let's round it to cube: .125 x .125 x .125

technically, the projected area changes all the time (rotation during the fall), but for our scientific purposes, let's assume, that it is falling down with one edge pointing downwards, so we have 2 sides projected at 45 degree angle.

Formula is: L x H * cos(angle) = .125*.125*cos(45) * 2 (since 2 sides are projected) = 0.022 m2 (cos(45) = .71)

drag coefficient for a cube is 0.8 (wiki it)

so, the result:

terminal velocity in air for 645Z = sqrt((2*1.5*9.8) / (1.18 * .022 * .8)) = 37.62m/s = 135.4km/h = 84.2mph

No. 645z can't do 150mph