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Old 02-29-2008, 09:29 AM   #4 (permalink)
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Let's stick to the metric system since it seems to use it, mostly?

1/2C_d is unit-less
A in m^2
rho is density, so kg/m^3
v is m/s, so v^3 is m^3/s^3

so we have kg*m^2/s^3
1 N is kg *m / s^2 -> Nm/s
1 J is Nm -> J/s
1 W is J/s, so we are left with pure watts
1 hp is 0.7457 kW

Essentially we take the result of the first part and *10^-3 / 0.7457, or multiply by 0.01341.

I'm not sure what the second part of the equation is, the addition, but in order to add numbers, the units MUST match. Pmotive=1/2*Cd*A*rho*v^3 is normal for a flat surface. What is Crr1?
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