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Zorluk: OrtaStopping Distance Components

A heavy vehicle is cruising at 50 mph50\text{ mph} when an unexpected road obstruction appears ahead. Telemetry data records the following distances during the stopping sequence: perception distance is 128 feet128\text{ feet}, driver reaction distance is 55 feet55\text{ feet}, air brake lag distance is 37 feet37\text{ feet}, and actual friction braking distance is 170 feet170\text{ feet}. What is the total distance traveled by the vehicle before the brake shoes begin actively pressing against the drums to decelerate the vehicle?

  1. A
    170 feet170\text{ feet}
  2. 220 feet220\text{ feet}Cevap
  3. C
    92 feet92\text{ feet}
  4. D
    390 feet390\text{ feet}

Cevap

220 feet220\text{ feet} is the total distance covered before mechanical braking begins.
Before brake shoes make contact with the brake drums, a commercial vehicle travels through three sequential non-decelerating stages: perception distance, reaction distance, and brake lag distance. Adding 128 feet128\text{ feet} (perception) + 55 feet55\text{ feet} (reaction) + 37 feet37\text{ feet} (air lag) results in 220 feet220\text{ feet} of total travel before braking force begins slowing the vehicle.

Adım Adım Çözüm

1
Identify all distinct phases that occur prior to the brake linings making contact with the drums.
The pre-braking phases consist of perception distance (128 ft128\text{ ft}), reaction distance (55 ft55\text{ ft}), and air brake lag distance (37 ft37\text{ ft}).
During perception, reaction, and air brake lag, the vehicle continues moving at highway speed without deceleration.
2
Calculate the cumulative sum of these three pre-braking components.
128 ft+55 ft+37 ft=220 feet128\text{ ft} + 55\text{ ft} + 37\text{ ft} = 220\text{ feet}.
Adding these components gives the total distance traveled before the brakes actively generate retarding force.

Anahtar Kavram

Components of Total Stopping Distance in Air Brake Systems
Tahmini Süre:1m 15s
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Konular

Stopping Distance Components

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