Kent is driving a car due west at a constant speed of 55 mph (miles per...

 

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Kent is driving a car due west at a constant speed of 55 mph (miles per hour) and sees a speed limit sign that says 45 mph. Kent immediately starts slowing down the car at a constant rate. The speed of the car is reduced to 45 mph right at the moment the car is passing the sign, and it took him 4.3 seconds to change the speed from 55 mph to 45 mph. Kent cruises the car for a distance of 1.2 miles due west at 45 mph after passing the sign. Then, Kent sees a red light and immediately applies the break to slow the car to a complete stop at a constant rate of 2.4 m/s². (a) What is the magnitude and the direction of the acceleration of the car during the time the speed changes from 55 mph to 45 mph? Answer in the unit of m/s2, and use north, south, east, or west to show the direction of the acceleration. [hint: You need to convert mph to m/s first. You can use the conversion 1mile = 1609 m.] (2 pt) (b) What is the displacement of the car during the time the speed changes from 55 mph to 45 mph? Answer in the unit of meters, and use north, south, east, or west to show the direction of the displacement. (2 pt) (c) How many seconds does Kent cruise the car at 45 mph until he sees the red light? Be careful with units. (2 pt) (d) How many seconds does it take Kent to slow the car from 45 mph to a complete stop? Be careful with units. (2 pt) (e) What is the displacement of the car during the time the car slows down to a complete stop? Answer in the unit of meters, and use north, south, east, or west to show the direction of the displacement. (2 pt) Kent is driving a car due west at a constant speed of 55 mph (miles per hour) and sees a speed limit sign that says 45 mph. Kent immediately starts slowing down the car at a constant rate. The speed of the car is reduced to 45 mph right at the moment the car is passing the sign, and it took him 4.3 seconds to change the speed from 55 mph to 45 mph. Kent cruises the car for a distance of 1.2 miles due west at 45 mph after passing the sign. Then, Kent sees a red light and immediately applies the break to slow the car to a complete stop at a constant rate of 2.4 m/s². (a) What is the magnitude and the direction of the acceleration of the car during the time the speed changes from 55 mph to 45 mph? Answer in the unit of m/s2, and use north, south, east, or west to show the direction of the acceleration. [hint: You need to convert mph to m/s first. You can use the conversion 1mile = 1609 m.] (2 pt) (b) What is the displacement of the car during the time the speed changes from 55 mph to 45 mph? Answer in the unit of meters, and use north, south, east, or west to show the direction of the displacement. (2 pt) (c) How many seconds does Kent cruise the car at 45 mph until he sees the red light? Be careful with units. (2 pt) (d) How many seconds does it take Kent to slow the car from 45 mph to a complete stop? Be careful with units. (2 pt) (e) What is the displacement of the car during the time the car slows down to a complete stop? Answer in the unit of meters, and use north, south, east, or west to show the direction of the displacement. (2 pt)

Answer rating: 100% (QA)

a First we need to convert 55 mph and 45 mph to meters per second 55 mph 55 1609 mhour 8826 ms 45 mp... View the full answer