Question

In: Physics

As a city planner, you receive complaints from local residents about the safety of nearby roads...

As a city planner, you receive complaints from local residents about the safety of nearby roads and streets. One complaint concerns a stop sign at the corner of Pine Street and 1st Street. Residents complain that the speed limit in the area (55 mph) is too high to allow vehicles to stop in time. Under normal conditions this is not a problem, but when fog rolls in visibility can reduce to only 155 feet. Since fog is a common occurrence in this region, you decide to investigate. The state highway department states that the effective coefficient of friction between a rolling wheel and asphalt ranges between 0.536 and 0.599, whereas the effective coefficient of friction between a skidding (locked) wheel and asphalt ranges between 0.350 and 0.480. Vehicles of all types travel on the road, from small VW bugs weighing 1150 lb to large trucks weighing 7440 lb. Considering that some drivers will brake properly when slowing down and others will skid to stop, calculate the miminim and maximum braking distance needed to ensure that all vehicles traveling at the posted speed limit can stop before reaching the intersection.

Solutions

Expert Solution

The speed limit in an area (55 mph) is too high to allow vehicles to stop in time.

v = 55 mph

converting mph into ft/s :

v = 24.5 ft/s

Since friction is the force slowing down the car.

Then, we have

F = m a f = m a

s m g = m a

s g = a                                                                    { eq.1 }

A maximum acceleration will be given by -

amax = [(0.480) (32 ft/s2)]

amax = 15.3 ft/s2

Then, the minimum braking distance which will be given by -

dmin = v2 / 2 amax

dmin = (24.5 ft/s)2 / [2 (15.3 ft/s2)]

dmin = [(600.25 ft2/s2) / (30.6 ft/s2)]

dmin = 19.6 ft

A minimum acceleration will be given by -

amin = [(0.350) (32 ft/s2)]

amin = 11.2 ft/s2

Then, the maximum braking distance which will be given by -

dmax = v2 / 2 amin

dmax = (24.5 ft/s)2 / [2 (11.2 ft/s2)]

dmax = [(600.25 ft2/s2) / (22.4 ft/s2)]

dmax = 26.7 ft


Related Solutions

As a city planner, you receive complaints from local residents about the safety of nearby roads...
As a city planner, you receive complaints from local residents about the safety of nearby roads and streets. One complaint concerns a stop sign at the corner of Pine Street and 1st Street. Residents complain that the speed limit in the area (55 mph) is too high to allow vehicles to stop in time. Under normal conditions this is not a problem, but when fog rolls in visibility can reduce to only 155 ft. Since fog is a common occurrence...
As a city planner, you receive complaints from local residents about the safety of nearby roads...
As a city planner, you receive complaints from local residents about the safety of nearby roads and streets. One complaint concerns a stop sign at the corner of Pine Street and 1st Street. Residents complain that the speed limit in the area ( 89 km/h) is too high to allow vehicles to stop in time. Under normal conditions this is not a problem, but when fog rolls in visibility can reduce to only 47 meters. Because fog is a common...
As a city planner, you receive complaints from local residents about the safety of nearby roads...
As a city planner, you receive complaints from local residents about the safety of nearby roads and streets. One complaint concerns a stop sign at the corner of Pine Street and 1st Street. Residents complain that the speed limit in the area (55 mph) is too high to allow vehicles to stop in time. Under normal conditions this is not a problem, but when fog rolls in visibility can reduce to only 155 ft. Since fog is a common occurrence...
As a city planner, you receive complaints from local residents about the safety of nearby roads...
As a city planner, you receive complaints from local residents about the safety of nearby roads and streets. One complaint concerns a stop sign at the corner of Pine Street and 1st Street. Residents complain that the speed limit in the area (55 mph) is too high to allow vehicles to stop in time. Under normal conditions this is not a problem, but when fog rolls in visibility can reduce to only 155 ft. Since fog is a common occurrence...
As a city planner, you receive complaints from local residents about the safety of nearby roads...
As a city planner, you receive complaints from local residents about the safety of nearby roads and streets. One complaint concerns a stop sign at the corner of Pine Street and 1st Street. Residents complain that the speed limit in the area (55 mph) is too high to allow vehicles to stop in time. Under normal conditions this is not a problem, but when fog rolls in visibility can reduce to only 155 ft. Since fog is a common occurrence...
You have just been hired as a community health program planner by a local city. The...
You have just been hired as a community health program planner by a local city. The city has noticed that childhood obesity rates have been steadily increasing and would like you to develop programs to help decrease childhood obesity in the city. You notice that the city does not have physical activity programs. Which model/framework would you use to develop such a program? Explain your answer.
The City Council wants to gather input from residents about the recreational opportunities in the city....
The City Council wants to gather input from residents about the recreational opportunities in the city. Categorize each technique as simple random sample, stratified sample, systematic sample, cluster sample, or convenience sample. a) Get an alphabetical list of all residents and question every 250th resident on the list. b) Have 10 volunteers go downtown on Saturday afternoon and question people that they see. The volunteers may quit when they have questioned 25 people. c) Get an alphabetical list of all...
Assume you work for OSHA (Occupational Safety and Health Administration) and have complaints about noise levels...
Assume you work for OSHA (Occupational Safety and Health Administration) and have complaints about noise levels from some of the workers at a state power plant. You charge the power plant with taking decibel readings at 2 different areas of the plant at different times of the day and week. The results of the data collection are listed. The safe hearing level is approximately 120 decibels Area1 Area 2 30 59 12 63 35 81 65 110 24 65 59...
2. The Guyana Water Inc. has received hundreds of complaints from residents of several villages in...
2. The Guyana Water Inc. has received hundreds of complaints from residents of several villages in East and West Canje, concerning the quality of water delivered to them. GWI wishes to ascertain (a) the veracity of claims made in the complaints, (b) the possible reasons for the problems highlighted and (c) possible solutions to identified problems. For these purposes, management has decided to undertake a survey. (a) Choose an appropriate sampling method and justify your choice. (b) State the objectives...
The City of Atlantis provides transit services for residents throughout the city. Suppose you are assigned...
The City of Atlantis provides transit services for residents throughout the city. Suppose you are assigned to determine transit ticket prices for the government of the City of Atlantis. How do you decide on the optimal ticket prices so that the city can provide an efficient level of transit services? Explain.  
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT