what is the stopping distance for a work truck weighing 4,685 lbs plus cargo of 1000 lbs traveling at 35mph?
To calculate the stopping distance of a vehicle, we need to consider two main factors: the thinking distance and the braking distance.
1. Thinking distance: This is the distance the vehicle travels while the driver reacts to a situation and applies the brakes. The average thinking distance is around 1 second or 22 feet at 35 mph.
2. Braking distance: This is the distance the vehicle travels while it slows down and comes to a complete stop. To calculate the braking distance, we need to consider the weight of the vehicle, the speed, and the road conditions.
The braking distance can be determined using the formula:
Braking Distance = (Speed²) / (2 x (Deceleration))
Where:
- Speed is the initial speed of the vehicle in feet per second.
- Deceleration is the rate at which the vehicle slows down. For an emergency stop on dry asphalt, a deceleration rate of 10 to 15 ft/s² is often used.
To convert mph to feet per second, multiply the speed by 1.47 (since 1 mph is approximately 1.47 feet per second).
Let's calculate the stopping distance:
Step 1: Convert the speed from mph to feet per second.
35 mph * 1.47 = 51.45 feet per second.
Step 2: Calculate the deceleration (let's assume 12 ft/s² for this example).
Deceleration = 12 ft/s².
Step 3: Plug the values into the formula.
Braking Distance = (51.45²) / (2 x 12)
Braking Distance = 2648.90 / 24
Braking Distance ≈ 110.37 feet
Step 4: Add the thinking distance.
Total Stopping Distance = Thinking Distance + Braking Distance
Total Stopping Distance ≈ 22 feet + 110.37 feet
Total Stopping Distance ≈ 132.37 feet
Therefore, the approximate stopping distance for a work truck weighing 4,685 lbs plus cargo of 1000 lbs traveling at 35 mph is 132.37 feet.