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8 57% Sat Jun 11 11 37 32 AM QA E Chrome File Edit View History Bookmarks People Window Help Josh Motion in one dimension C Physics question I Chegg www.webassign.net /web/Student/Assignment-Responses/last?dep 13907357 i Apps Book Apple YouTube home Watch Live Sports E O tech Destiny l The BNg faculty.pnc.edu/ptes OTR DestinyTracker De nyLFG.N C. Henry Edwards, 2/4 2/2 2/2 6/8 (75.0% Points Assignment submission For this assignment, you submit answers by question parts. The number of submissions remaining for each question part only changes if you submit or change the answer. Assignment Scoring Your last submission is used for your score. 2/4 points Previous Answers CJ10 2.P.014. My Notes Ask Your Teacher Review Conceptual Example 6 as background for this problem. A car is traveling to the left, which is the negative direction. The directio of n travel remains the same throughout this problem. The car's initial speed is 27.0 m/s, and during a 5.2 s interval, it changes to a final speed. In each case, find the acceleration magnitude and algebraic sign and whether or not the car is decelerating a) The final speed is 32.5 m/s. x m/s and the car is accelerating 1.06 (b) The final speed is 24.8 m/s. x m/s2 and the car is decelerating 2.2 Additional Materials Section 2.3 Submit Answer Save Progress Practice Another Version 2. C+ 2/2 points I Previous Answers CJ10 2.P.017. My Notes Ask Your Teacher

Explanation / Answer

  The car is traveling in the negative direction at a speed of 27 m/s, so its velocity is -27 m/s. I assume we want the constant acceleration, if so we can use the kinematic equations provided via your teacher, book and internet. I'm going to use Vf = Vi + a*t

a) we know we have a:
Vf = -32.5 m/s
Vi = -27 m/s
t = 5.2 s

Vf = Vi + a*t
re-arrange for acceleration:
a = (Vf - Vi)/t
a = (-32.5 - (-27))/5.2
a = -1.057m/s^2

the car is accelerating because it is changing it is increasing its speed in the same direction (the negative direction)

b)
Vf = -24.8 m/s
Vi = -27 m/s
t = 5.2 s

Vf = Vi + a*t
re-arrange for acceleration:
a = (Vf - Vi)/t
a = (-24.8 - (-27))/5.2
a = 0.42 m/s^2

The car is DE-accelerating because the acceleration is in the opposite direction of the car's motion.

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