Police use the formula:
v
=
√
20
L
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 111 feet long. Approximately how fast was the car traveling? Round your answer to the nearest tenth (one decimal place) of a unit.
To estimate the speed of a car, the police use the formula:
v = √20L
In this formula, v represents the speed of the car in miles per hour, and L represents the length of the skid marks in feet.
Given that the length of the skid marks is measured to be 111 feet, we can substitute this value into the formula and solve for v.
v = √20(111)
First, calculate 20 times 111:
20 * 111 = 2220
Now, take the square root of 2220:
√2220 ≈ 47.1
Rounding the answer to the nearest tenth, we get:
v ≈ 47.1
So, the car was traveling at approximately 47.1 miles per hour.