SOLUTION: Police use the formula V (L) = sqrt(20L) to estimate the speed of a car in miles per hour, based on the length, L, in feet, of its skid marks when suddenly braking on a dry, asphal

Algebra ->  Radicals -> SOLUTION: Police use the formula V (L) = sqrt(20L) to estimate the speed of a car in miles per hour, based on the length, L, in feet, of its skid marks when suddenly braking on a dry, asphal      Log On


   



Question 1154785: Police use the formula V (L) = sqrt(20L) to estimate the speed of a car in miles per hour, based on the length, L, in feet, of its skid marks when suddenly braking on a dry, asphalt road.
At the scene of an accident, a police officer measures a car's skid marks to be 229 feet long. Approximately how fast was the car traveling?
_______
One of the people involved in the accident says that he was traveling 48 mph when he braked. How long in feet should his car's skid marks be?
_________

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+V%28L%29+=+sqrt%28+20L+%29+
+V%28229%29+=+sqrt%28+20%2A229+%29+
+V%28229%29+=+sqrt%28+4580+%29+
+V%28229%29+=+67.676+
approx. 68 mi/hr
-------------------------
+V%28L%29+=+48+
+48+=+sqrt%28+20L+%29+
Square both sides
+2304+=+20L+
+L+=+115.2+
115.2 ft