Police use the formula v Squareroot 20L to estimate the spe

Police use the formula: v = Squareroot 20L to estimate the speed of a car, v, 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 203 feet long. Approximately how fast was the car traveling? Round your answer to the nearest tenth (one decimal place) of a unit. Answer: The car was traveling at approximately miles per hour.

Solution

given skid marks when braking = 203 feet

speed of car = sqrt(20*L)

put L = 203

Speed of car = sqrt(20*203) = sqrt(4060) = 63.7 miles per hour

so car was traveling at approximately 63.7 miles per hour