A particle that is moving along a straight line decelerates uniformly from 40 cm/s to 20 cm/s in 5.0 s and then has a constant acceleration of 20 cm/s² during the next 4.0 s.The average speed over the whole time interval is A)57 cm/s B)140 cm/s C)86 cm/s D)43 cm/s E)97 cm/s

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Quizplus · Accepted Answer

The particle first decelerates from 40 cm/s to 20 cm/s over 5 seconds, covering a distance of 150 cm. Then, it accelerates at 20 cm/s² for 4 seconds, reaching a final speed of 100 cm/s and covering an additional 240 cm. The total distance is 390 cm over 9 seconds, giving an average speed of 43.33 cm/s, rounded to 43 cm/s.

A Particle That Is Moving Along a Straight Line Decelerates