EBK PRINCIPLES OF HIGHWAY ENGINEERING A
6th Edition
ISBN: 9781119299332
Author: WASHBURN
Publisher: JOHN WILEY+SONS,INC.-CONSIGNMENT
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
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
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
A car is traveling at 76 mi/hr down a 3% grade on poor, wet pavement. The car's braking efficiency is 90%. The brakes were applied 320 ft before impacting an object. The car had an antilock braking system, but the system failed 200ft after the brakes had been applied (wheels locked). What speed was the car traveling at just before it impacted the object? (Assume theoretical stopping distance, ignore air resistance, and let Frl=0.015)
A car is traveling up a 1.5% grade at 65 mi/hr on good, wet pavement. The driver brakes to
try to avoid hitting a cone on the road that is 300 ft ahead. The driver's reaction time is 1.5
second. When the driver first applies the brakes, a software flaw causes the braking
efficiency to lower to 0.8 for 100 ft. After the initial 100 ft, the braking efficiency returns
to 1.0. How fast will the driver be going when the cone on the road is hit if the coefficient
of rolling resistance is constant at 0.015? (Assume minimum theoretical stopping distance
and ignore aerodynamic resistance.)
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]
Chapter 2 Solutions
EBK PRINCIPLES OF HIGHWAY ENGINEERING A
Ch. 2 - Prob. 1PCh. 2 - Prob. 2PCh. 2 - Prob. 3PCh. 2 - Prob. 4PCh. 2 - Prob. 5PCh. 2 - Prob. 6PCh. 2 - Prob. 7PCh. 2 - Prob. 8PCh. 2 - Prob. 9PCh. 2 - Prob. 10P
Ch. 2 - Prob. 11PCh. 2 - Prob. 12PCh. 2 - Prob. 13PCh. 2 - Prob. 14PCh. 2 - Prob. 15PCh. 2 - Prob. 16PCh. 2 - Prob. 17PCh. 2 - Prob. 18PCh. 2 - Prob. 19PCh. 2 - Prob. 20PCh. 2 - Prob. 21PCh. 2 - Prob. 22PCh. 2 - Prob. 23PCh. 2 - Prob. 24PCh. 2 - Prob. 25PCh. 2 - Prob. 26PCh. 2 - Prob. 27PCh. 2 - Prob. 28PCh. 2 - Prob. 29PCh. 2 - Prob. 30PCh. 2 - Prob. 31PCh. 2 - Prob. 32PCh. 2 - Prob. 33PCh. 2 - Prob. 34PCh. 2 - Prob. 35PCh. 2 - Prob. 36PCh. 2 - Prob. 37PCh. 2 - Prob. 38PCh. 2 - Prob. 39PCh. 2 - Prob. 40P
Knowledge Booster
Learn more about
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
- 1. A car is approachin an intersection with velocity 35 mph. When the car is at a distance of 200 ft from the intersection, the signal turned yellow. If the driver decides to break, will he be able to stop safely? The driver's reaction time is 1.5 s. Assume the road surface as leveled. The maximum braking effort is applied. Will your answer change, if the grade of the road surface is downhill 3%? A car is at a distance of 200 ft from an intersection stop line when the signal turned yellow. What should be the minimum speed of the car (miles/hour) if the driver decides to apply brake and is just able to stop at the line? Use reaction time of 1.5 s and the road surface has zero grade.arrow_forwardA 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.arrow_forwardA car is driving at 75 mph down a 4.0 % grade on poor, wet pavement. The car's braking efficiency is 90%. The driver saw an object which is 480 ft away and applied the brake, and his reaction time was 1.0 second. The car's antilock braking system (ABS) works. Just after seeing the object, which of the following is closest to the distance (in ft) traveled before applying the brake? (Assume theoretical stopping distance ignore air resistance and let yb= 1.04 and fr = 0.015). 153 ft B) 127 ft 135 ftarrow_forward
- 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.arrow_forwardThe car's braking distance from a velocity of v= 96 km/hr is 45 m on a level pavement. Assuming that the braking force is independent of the grade of the pavement, determine the car's braking distance from the same velocity when it is (a) Going up a 10-percent incline (b) Going down an 8° inclinearrow_forwardA car traveling at 45 mph on a poor, wet pavement has a braking efficiency of 87%. The brakes were applied 100 feet before hitting an obstacle in the road. The road is uphill for 40 feet and then is level for the remainder of the way. The car had a maximum coefficient of road adhesion in the sloped portion of the poor, wet roadway and but as soon as it started going on the level portion its coefficient of road adhesion reduced to 0.3. Assuming that the car struck the obstacle at 30 mph, what was the grade of the hill? Assume practical stopping distance equation applies.arrow_forward
- An auto, equipped with only front wheel brakes, has a wheelbase of 120 in. with its c.g. located 60 in. ahead of the rear wheels and 36 in. above the pavement. If f = 0.80 at the tires, compute the minimum distance in which the auto can be brought to rest from a speed of 60 mph if the driver’s reaction time before applying the brakes is 3/4 sec.arrow_forwardplease answer quicklyarrow_forwardPlease solve if step by step... As soon as possiblearrow_forward
- 2-A motorist travelling at 100 km/h on a highway needs to take the next exit, which has a speed limit of 50 km/h. 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, find the braking distance (expressed in m) from the exit ramp.arrow_forwardA car is traveling at 70 mi/h on a level section of road with good, wet pavement. Its antilock braking system (ABS) only starts to work after the brakes have been locked for 100 ft. If the driver holds the brake pedal down completely, immediately locking the wheels, and keeps the pedal down during the entire process, how many feet will it take the car to stop from the point of initial brake application? (The braking efficiency is 80% with the ABS not working and 100 % with the ABS working. Use theoretical stopping distance and ignore air resistance. Let frl = 0.02 when the brakes are locked, but complete the frl once the ABS becomes active.)arrow_forwardpart a, assuming decelerat on rate is unknown bu the friction factor=0.2. 2. A driver traveling down a 4% grade collides with a roadside object. The roadway has a posted speed limit is 60mph. The driver mentioned he strictly followed the speed limit. The accident investigation team indicates: braking skid marks started 300 ft before the struck object. a. If the friction factor was measured as 0.2, estimate the speed of the vehicle when it struck the object. b. Estimate the minimum required friction factor so the 300 ft skid marks can allow the driver to safely stop before he would strike the object.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Structural Analysis (10th Edition)Civil EngineeringISBN:9780134610672Author:Russell C. HibbelerPublisher:PEARSONPrinciples of Foundation Engineering (MindTap Cou...Civil EngineeringISBN:9781337705028Author:Braja M. Das, Nagaratnam SivakuganPublisher:Cengage Learning
- Fundamentals of Structural AnalysisCivil EngineeringISBN:9780073398006Author:Kenneth M. Leet Emeritus, Chia-Ming Uang, Joel LanningPublisher:McGraw-Hill EducationTraffic and Highway EngineeringCivil EngineeringISBN:9781305156241Author:Garber, Nicholas J.Publisher:Cengage Learning
Structural Analysis (10th Edition)
Civil Engineering
ISBN:9780134610672
Author:Russell C. Hibbeler
Publisher:PEARSON
Principles of Foundation Engineering (MindTap Cou...
Civil Engineering
ISBN:9781337705028
Author:Braja M. Das, Nagaratnam Sivakugan
Publisher:Cengage Learning
Fundamentals of Structural Analysis
Civil Engineering
ISBN:9780073398006
Author:Kenneth M. Leet Emeritus, Chia-Ming Uang, Joel Lanning
Publisher:McGraw-Hill Education
Traffic and Highway Engineering
Civil Engineering
ISBN:9781305156241
Author:Garber, Nicholas J.
Publisher:Cengage Learning