The forces acting on the car are caused by internal, tire, and air
resistance. The resultant of these forces, the total drag force, F_{D}, can be estimated by the following
equation:

Where:

- c

c

m = mass of vehicle [kg]

A = frontal surface area [m

g = 9.8 m/s

r = density of are, 1.2 kg/m

The power output requirement can be determined from the drag force given above
and the vehicle velocity.

Given the mass of a vehicle and its frontal surface area, a plot can be drawn showing the power requirements for a range of speeds. The Power Requirement Applet plots this relationship.

The power required to accelerate to a given speed is also of interest. More power is required for more acceleration. The Acceleration Applet compares the power required to accelerate from 0 to 60 mph for a range of times.

The basic definition for the acceleration force (neglecting drag !) is given by:

Assuming that the force required to accelerate a vehicle from 0 to 60 mph can be determined from the above equation, then the power necessary to accelerate to a given velocity is:

Where:

- m = mass of the vehicle

a = acceleration = DV/DT

DV = 60 - 0 = 60 mph = 26.82 m/s

V = final velocity, 60 mph

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