View Single Post
  #12 (permalink)  
Old 07-13-2008, 05:27 PM
cojaro's Avatar
cojaro cojaro is offline
Member
iTrader: (0)
 
Join Date: Jul 2007
Location: Memphis, TN
Posts: 1,699
Rep Power: 1029
cojaro relies on Rep Points to livecojaro relies on Rep Points to livecojaro relies on Rep Points to livecojaro relies on Rep Points to livecojaro relies on Rep Points to livecojaro relies on Rep Points to livecojaro relies on Rep Points to livecojaro relies on Rep Points to livecojaro relies on Rep Points to livecojaro relies on Rep Points to livecojaro relies on Rep Points to live
Send a message via AIM to cojaro
With some Physics, you could find out the drag yourself! =)

KE(i) + PE(i) = KE(f) + PE(f) + E(lost)
The sum of the initial kinetic and potential energies is equal to the sum of the final kinetic and potential energies and energy lost, which in the case of cars, is the rolling resistance and drag

We get:

½mv(i)² + mgh(i) = ½mv(f)² + mgh(f) + E(r.r.) + E(drag)
m = mass
v = velocity
g = gravitational acceleration
h = height

And we can change this from an energy problem to a work problem!

½mΔv² + mgΔh = F(r.r.)d + F(C)d
d = distance traveled
d can be found by d = ½(v(i) + v(f))Δt

½mΔv² + mgΔh = C(r.r.)Nd + ½ρv(f)²C(d)Ad
ρ = air density
A = cross-sectional area (largest)
C(d) = drag coefficient

C(r.r.) = coefficient of rolling friction of the tire(CRF)

½mΔv² + mgΔh = d(C(r.r.)mg + ½ρv(f)²C(d)A)
ρ ≈ 1.2kg/m³
m = 1103.14kg
mg = 1103.14kg * 9.81m/s² = 10821.80N


551.57Δv² + 10821.80Δh = C(r.r.)10821.80d + 0.6v(f)²C(d)Ad

[551.57Δv² + 10821.80Δh - C(r.r.)10821.80d] \ [0.6v(f)²Ad] = C(d)

Ta-da! I ♥ Physics. And I hope I got all of that right!

What you'll need is the rolling resistance rating of your tires, and the cross-sectional area of the fit. Everything else can be found! =)
__________________
2007 NBP Fit Sport MT
Honda Floor Mats || Honda Cargo Net || 35% tint || custom CAI || Blox shift knob || LED dome + cargo lights || Megan axle-back || Zeta dead pedal || "Dirty White Boy" air freshener :-D



http://www.fitfreak.net/forums/fit-suspension-brake-modifications/21657-suspension-theory.html || http://www.fitfreak.net/forums/showthread.php?t=24942

Last edited by cojaro; 07-13-2008 at 09:14 PM.
Reply With Quote