strategy for solution?

[Rob and/or Kristin Spencer <rspencer@KIVA.NET>]

Is there a way to figure out a maximum or minimum speed that the vehicle had to be traveling?  Without any knowledge of how fast the car is going after the collision...and also the effect of air on the pedestrian...I am not sure where to go...what I have follows the description:

 

Pedestrian is crossing the street.  Normal pace, not running or anything
like that.  He weighs 270 lbs and is 5 foot 7 inches tall.  He is struck by
a 1986 Oldsmobile sedan (88 Delta Royale), curb weight approximately 3,186
lbs.  Pedestrian is thrown 38 feet from the point of impact.  I would like
to know how fast the 1986 sedan was travelling at the time of the impact.
You may assume, for purposes of this question, that the pedestrian was
thrown and not dragged.

 

vfc = (3186vic + 270vfp) / 3186                     from conservation of momentum

 

vfc = final velocity of the car

vic = initial velocity of the car

vfp = launch velocity of pedestrian

 

vfp can be figured from kinematics to be >= 34.9 ft / s     (assuming launch angle at 45 degrees w/ no air resistance........with air and non-ideal launch angle, vfp would have to be greater than 34.9 ft/s or 23.8 mph)

 

vfc = (3186 vic +270(23.8)) / 3186

 

vfc = (3186 vic + 6426) / 3186

 

I don't know where to go from here...any help would be appreciated.

 

rob spencer