document.write( "Question 682077: Vehicle Car A is now passing a truck that is 90 feet long. Vehicle A is traveling 40 mph( or 60 feet per seconds) and truck B is traveling 30mph (or 45 feet per seconds. Vehicle A will being passing maneuver $ seconds behind the trucj to allow the truck to see him.Vehivle A will return to his lane when he is 60 feet ahead of truck B.
\n" ); document.write( "What is the distance between truc B & vehicle A after A passses the truck and return to his lane? And what us the Total amount Vehicle A must travel to complete this maneuver?
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Algebra.Com's Answer #423085 by KMST(5328)\"\" \"About 
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MY INTERPRETATION OF THE PROBLEM:
\n" ); document.write( "Car A is now passing a truck (truck B) that is 90 feet long.
\n" ); document.write( "Car A is traveling at 60 feet per second all the time,even when changing lanes, and
\n" ); document.write( "truck B is traveling at 45 feet per second all the time.
\n" ); document.write( "Car A will begin the passing maneuver 4 seconds behind the truck,
\n" ); document.write( "meaning 4 seconds before it would hit the truck if it stayed on the same lane.
\n" ); document.write( "Car A will return to his lane when it is 60 feet ahead of truck B,
\n" ); document.write( "meaning when the car's front bumper is 60 feet ahead of the truck's front bumper.
\n" ); document.write( "MY INTERPRETATION OF THE PROBLEM'S QUESTIONS:
\n" ); document.write( "What is the distance (empty space) between truck B & vehicle A after A passes the truck and returns to its original lane?
\n" ); document.write( "What is the total distance vehicle A must travel to complete this maneuver?
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\n" ); document.write( "THE PROBLEM WITH THIS PROBLEM is that there is too much open to interpretation, so my answers may not be the expected answers.
\n" ); document.write( "It is quite possible that a less realistic approach was expected.
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\n" ); document.write( "We would use the speeds in feet per second (ft/s) rather than in mph.
\n" ); document.write( "Since the difference between the speed of the car and the speed of the truck is \"60-45=15\"ft/s, before passing the truck, the car would be reducing its distance from the truck at a rate of \"60-45=15\"ft/s.
\n" ); document.write( "At that rate, in \"4\" seconds, the car would reduce its distance to the truck by
\n" ); document.write( "\"4%2A15=60\"feet, so the car would start the passing maneuver when \"60\"ft from the truck.
\n" ); document.write( "If I were driving car A, I would drive in the middle of each lane when not changing lanes.
\n" ); document.write( "To change lanes, I would turn at a \"41.4%5Eo\" angle towards the other lane.
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\n" ); document.write( "That way, my \"60\"ft/s speed would have a forward component of \"45\"ft/s, matching the speed of the truck.
\n" ); document.write( "\"60%2Acos%2841.4%5Eo%29=60%2A0.75=45\".
\n" ); document.write( "The sideways component of my \"60\"ft/s speed would be \"39.7\"ft/s.
\n" ); document.write( "The lane width in my highway would be \"12\"ft, and
\n" ); document.write( "at a lateral speed of \"39.7\"ft/s, I would move \"12\"ft laterally in
\n" ); document.write( "\"12%2F39.7=0.3\"seconds.
\n" ); document.write( "While doing the lane changes at that angle (before and after passing the truck), I would spend
\n" ); document.write( "\"2%2A0.3\"seconds moving at the same forward \"45\"ft/s speed as the truck.
\n" ); document.write( "In between lane changes, on the passing lane, I would be gaining on the truck,
\n" ); document.write( "advancing forward from being \"4\" seconds behind the truck
\n" ); document.write( "(\"60\"feet),
\n" ); document.write( "to having my front bumper \"60\"ft ahead of the front bumper of the truck.
\n" ); document.write( "Since my car is \"16\"feet long, that would mean my rear bumper would be
\n" ); document.write( "\"60-16=44\"feet in front of the front bumper of the truck after passing.
\n" ); document.write( "That would be my answer to the first question, but I do not think that is the expected answer, because it depends on the length of car A, the driver's lane change strategy and the width of the lane.
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\n" ); document.write( "From the point of view of the truck driver, the truck is not moving, and the car is advancing at \"15\"ft/s while on the passing lane.
\n" ); document.write( "Also from the point of view of the truck driver, the car covers a distance of
\n" ); document.write( "\"60%2B90%2B60=210\"feet while moving forward on the passing lane.
\n" ); document.write( "At \"15\"ft/s, those \"210\"feet would be covered in
\n" ); document.write( "\"210%2F15=14\"seconds.
\n" ); document.write( "The whole passing maneuver would take
\n" ); document.write( "\"0.6%2B14=14.6\"seconds, \"0.6\" for the two lane changes, and \"14\"seconds on the fast lane.
\n" ); document.write( "During that time, the truck would have advanced at \"45\"ft/s, covering
\n" ); document.write( "\"14.6%2A45=657\"feet.
\n" ); document.write( "The car would have advanced \"210+feet\" relative to the truck, advancing
\n" ); document.write( "\"657%2B210=867\"feet forward during the whole passing maneuver,
\n" ); document.write( "while on a lane shifting trajectory of total length
\n" ); document.write( "\"14.6%2A60=876\"feet, and that would be my answer to the second question.
\n" ); document.write( "The two slanted lane change portions of that trajectory would have accounted for
\n" ); document.write( "\"0.6%2A60=36\"feet.
\n" ); document.write( "During the \"14\"seconds moving straight forward on the passing lane, the car would have covered
\n" ); document.write( "\"14%2A60=840\"feet.
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