Example: Finding the Speed of a Car from Skid Marks

In the context of accident investigation, forensic teams use the length of skid marks on the pavement to estimate how fast a vehicle was traveling before the brakes were applied. If the length of the skid marks is $d$ feet, which of the following formulas is used to find the speed $s$ of the car in miles per hour?

A forensic accident investigator measures the length of skid marks on a road to be $d$ feet. To calculate the vehicle's speed $s$ in miles per hour right before the brakes were applied, the investigator uses the formula $s = 24\sqrt{d}$.

In the forensic formula $s = \sqrt{24d}$, which is used by investigators to estimate a vehicle's speed from the length of skid marks, match each component of the formula with its correct definition or unit of measurement.

An accident investigator is training a new recruit on how to use physical evidence at a crash scene. To estimate a vehicle's speed from skid marks using the standard forensic formula, arrange the following steps in the correct logical order, starting with the first action taken.

Forensic Speed Calculation Formula

A fleet safety manager is reviewing an accident report involving a company delivery van. The report uses the formula $s = \sqrt{24d}$ to estimate the vehicle's speed ($s$) in miles per hour prior to braking. For this calculation to be accurate, the length of the skid marks ($d$) must be measured in ____.

Commercial Fleet Accident Investigation