To calculate the dynamic hydroplaning speed of a vehicle, which value is multiplied after taking the square root of the tire pressure?

The calculation of dynamic hydroplaning speed for a vehicle involves taking the square root of the tire pressure in pounds per square inch (psi) and then multiplying it by a specific coefficient. In this context, the correct multiplier is 10.3.

This multiplier is derived from empirical studies and represents the relationship between tire pressure and the speed at which hydroplaning occurs. Hydroplaning happens when a vehicle's tires lose contact with the road due to water on the surface, and is influenced by factors including tire tread design, water depth, and speed.

Using the multiplier of 10.3 is beneficial as it provides a practical estimate for drivers and emergency vehicle operators to understand the critical speed at which hydroplaning can start. Understanding this speed is vital for maintaining vehicle control in adverse weather conditions, particularly when responding to emergencies. Therefore, the dynamic hydroplaning speed can be calculated as follows:

Dynamic Hydroplaning Speed (in mph) = 10.3 * √(Tire Pressure in psi).

This approach helps ensure that operators are prepared for the risks associated with high speeds on wet surfaces, contributing to safer emergency response operations.