Emergency Vehicle Dynamics & Physics Flashcards

During hard emergency braking, vehicle weight transfers to which end of the vehicle?

Answer: The front axle

Inertia causes the vehicle's mass to continue forward during braking, transferring weight onto the front axle and increasing front-tire traction.

What is 'understeer' in vehicle dynamics?

Answer: When front wheels lose traction and the vehicle plows straight despite steering input

Understeer occurs when front tires lose grip, causing the vehicle to continue in a straight path regardless of the steering wheel input.

What is 'oversteer' in vehicle dynamics?

Answer: When the rear of the vehicle slides outward during a turn

Oversteer occurs when rear tires lose traction, causing the rear end to swing outward and the vehicle to rotate beyond the intended turn.

During rapid acceleration from a stop, vehicle weight transfers to which axle?

Answer: Rear axle

Inertia resists forward acceleration, causing weight to shift rearward and reducing traction at the front axle during hard acceleration.

How does a higher center of gravity affect rollover risk in an emergency vehicle?

Answer: Significantly increases rollover risk, especially during sharp turns

A higher center of gravity increases the lever arm of the tipping moment, making lateral forces more effective at rolling the vehicle.

Why is understanding weight transfer important for emergency vehicle operators?

Answer: To predict handling changes and maintain control during acceleration, braking, and cornering

Understanding weight transfer allows operators to anticipate how the vehicle will respond and make proactive, precise control inputs.

What is 'threshold braking'?

Answer: Applying maximum brake pressure just below the wheel lockup point

Threshold braking maximizes deceleration by applying pressure right at the edge of wheel lockup without triggering a skid.