Principles of Highway Engineering and Traffic Analysi (NEW!!)
6th Edition
ISBN: 9781119305026
Author: Fred L. Mannering, Scott S. Washburn
Publisher: WILEY
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Chapter 2, Problem 24P
To determine
The speed of the car when the stopped traffic is hit if the coefficient of rolling resistance is constant at
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An auto, equipped with only front wheel brakes, has a wheelbase of 120 in. with its c.g.
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1. A driver is travelling at 50 mph is 80 m from a wall ahead, if the driver applies the brake immediately at t=2 secs, and begins slowing down at 10m/s^2.a. Find the distance from the stopping point to the wall.b. Determine the braking time or the time during deceleration.c. Determine the average skid resistance, assuming brake efficiency of 70%.
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A car is approaching toward an intersection with speed 45 mph. The road has a downhill grade of 1%. When the car is at a distance of 250 ft from the intersection, the signal turned yellow. If the driver applies brake and the reaction time of the driver is 1.5 s, will the driver be able to come to a complete stop? Justify your answer with calculations. Assume braking friction coefficient of 0.35.
Chapter 2 Solutions
Principles of Highway Engineering and Traffic Analysi (NEW!!)
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Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, civil-engineering and related others by exploring similar questions and additional content below.Similar questions
A car is traveling up a 3% grade, with the speed of 85mph, on a road that has good, wet pavement. A deer jumps out onto the road and the driver applies the brakes 290-ft from it. The driver hits the deer at a speed of 20mph.If the driver did not have antilock brakes, and the wheels were locked the entire distance, would a deer-impact speed of 20mph be possible? (Hint: check the braking efficiency) [Use Theoretical Stopping Distance]
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A motorist travelling at 100 km/hr on a highway needs to take the next exit, which
has a speed limit of 50 km/hr. The section of the roadway before the ramp entry has
a downgrade of 3% and coefficient of friction (f) is 0.35. In order to enter the ramp
at the maximum allowable speed limit, determine the braking distance (expressed in
m) from the exit ramp.
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A car is traveling up a 2% grade at 70 mi/h on good, wet pavement. The driver brakes to try to avoid hitting stopped traffic that is 250 ft ahead. The driver's reaction time is 0.5 s. At first, when the driver applies the brakes, a software flaw causes the anti-lock braking system to fail (brakes work in non-anti-lock mode with 80% efficiency), leaving 80 ft skid marks. After the 80 ft skid, the anti-lock brakes work with 100% efficiency. How fast will the driver be going when the stopped traffic is hit if the coefficient of rolling resistance is constant at 0.013? (assume minimum theoretical stopping distance and ignore aerodynamic resistance)
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A student trying to test the braking ability of his car, determined that he needed 32 ft. More to stop his car downhill on a particular road than uphill when driving at 55 mph. Assuming that the coefficient of friction between the tires and the pavement is 0.30. Determine the braking distance downhill and the percent grade of the highway at that section of the road.
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compute the braking distance for a car moving at an initial velocity of 80 kph and a final velocity of 60 kph. slope of roadway is +6% the coefficient of friction between road pavement and tries is 0.17, and the perception time is 3/4 seconds.
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A driver driving at 69 kph at a straight flat portion of the highway suddenly encounters an obstruction. He applies his brakes. If the coefficient of friction of the roadway to the tires is equal to 0.5, calculate the maximum safe distance (rounded to the nearest meters) the driver can apply his brakes to avoid collision.
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A car is traveling at 60 mi/h on good, wet pavement. It has a wheelbase of 110 inches with the center of gravity 50 inches behind the front axle and at a height of 24 inches above the pavement surface. Determine the percentage of braking force that the braking system should allocate to the rear axle.
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What should be the maximum speed (mph) of a car traveling on a leveled (zero grade) road surface if the available stopping sight distance is 400 ft? Assume 1.5 s of reaction time and braking friction coefficient of 0.35.
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A driver is driving at 75 kph when a dog suddenly appeared and stopped at the middle of the road. Determine the distance the vehicle would move before the driver could activate the brakes. Assume PRT is 2.50 secs.
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If the vehicle is 250 m away when the driver sees the dog, will the dog be hit by the vehicle?
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The rated speed of a highway curve of 200 ft radius is 40 mph. If the coefficient of friction between the tires and the road is 0.26, (a) What is the maximum speed at which a car can round the curve without skidding?
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