EVOC Emergency Vehicle Dynamics & Physics

Question 1

When a driver doubles their speed, how does stopping distance change?

Accepted Answer

It quadruples (4×)

Answer

Stopping distance is proportional to the square of speed, so doubling speed quadruples the stopping distance.

Question 2

What is the correct braking technique for a vehicle equipped with anti-lock brakes (ABS) during an emergency stop?

Accepted Answer

Apply firm, continuous pressure and hold

Answer

ABS-equipped vehicles require firm, sustained pedal pressure; the system automatically modulates brake force to prevent wheel lockup.

Question 3

Which single factor has the greatest impact on total stopping distance at highway speeds?

Accepted Answer

Vehicle speed

Answer

Since stopping distance increases with the square of speed, vehicle speed has an exponential—not linear—effect on total stopping distance.

Question 4

What causes brake fade during prolonged heavy braking?

Accepted Answer

Overheating of brake components reducing friction effectiveness

Answer

Brake fade occurs when excessive heat builds up in the braking system, lowering the friction coefficient between pads and rotors.

Question 5

How does a heavier vehicle load affect stopping distance?

Accepted Answer

Increases stopping distance due to greater kinetic energy

Answer

A heavier load increases the vehicle's kinetic energy, which requires more distance and braking force to dissipate.

EVOC - Emergency Vehicle Operator Course Certification Practice Test