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Zorluk: OrtaStopping Distance Components

An interstate freight carrier is evaluating telemetry data following an emergency stop by an air-brake combination vehicle traveling at 65 mph65\text{ mph} on a dry asphalt highway. The investigation records a perception distance of 168 feet168\text{ feet}, a reaction distance of 72 feet72\text{ feet}, an air brake lag distance of 38 feet38\text{ feet}, and an overall total stopping distance of 584 feet584\text{ feet}. Based on the standard four-component formula for air brake stopping distance, what was the vehicle's actual braking distance?

  1. A
    344 feet344\text{ feet}
  2. 306 feet306\text{ feet}Cevap
  3. C
    278 feet278\text{ feet}
  4. D
    378 feet378\text{ feet}

Cevap

The vehicle's actual braking distance was 306 feet306\text{ feet}.
For commercial motor vehicles equipped with air brakes, total stopping distance consists of four sequential components: perception distance, reaction distance, air brake lag distance, and braking distance. Subtracting the three pre-braking components (168 ft+72 ft+38 ft=278 ft168\text{ ft} + 72\text{ ft} + 38\text{ ft} = 278\text{ ft}) from the total stopping distance of 584 ft584\text{ ft} isolates the actual braking distance as 306 feet306\text{ feet}.

Adım Adım Çözüm

1
Identify the standard stopping distance formula for commercial vehicles equipped with air brakes.
Total Stopping Distance=Perception Distance+Reaction Distance+Brake Lag Distance+Braking Distance\text{Total Stopping Distance} = \text{Perception Distance} + \text{Reaction Distance} + \text{Brake Lag Distance} + \text{Braking Distance}
Air brake systems require air to flow through the lines and fill the brake chambers before mechanical friction begins, creating a fourth distinct component known as brake lag distance.
2
Sum the recorded pre-braking distance components.
168 ft+72 ft+38 ft=278 ft168\text{ ft} + 72\text{ ft} + 38\text{ ft} = 278\text{ ft}
Determining the total distance traveled before the brake linings actively apply frictional force against the drums.
3
Subtract the pre-braking distance from the total stopping distance to isolate braking distance.
Braking Distance=584 ft−278 ft=306 ft\text{Braking Distance} = 584\text{ ft} - 278\text{ ft} = 306\text{ ft}
Braking distance is the physical distance traversed while the vehicle is actively decelerating to a complete halt.

Anahtar Kavram

Four components of total stopping distance in air brake systems: perception distance, reaction distance, brake lag distance, and braking distance.
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Konular

Stopping Distance Components

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