A particle moves along a straight line so that its position (in meters) at time…

MATHEMATICS · Multi-part · CBSE · Mathematics · Applications of Derivatives · Applications of Derivatives

Problem

A particle moves along a straight line so that its position (in meters) at time tt seconds is given by s(t)=3t3−12t2+9t+5s(t)=3t^{3}-12t^{2}+9t+5 for 0≤t≤40\le t\le 4. (a) Derive an expression for the particle’s velocity v(t)v(t). (b) Explain why any interior time tt at which the particle attains a maximum or minimum position must satisfy v(t)=0v(t)=0, and discuss why the endpoints t=0t=0 and t=4t=4 must also be examined. (c) Identify all times in [0,4][0,4] at which the particle could achieve an extreme position, and classify each as a critical point or an endpoint. Justify your classifications. (d) Using your results from part (c), determine the greatest distance of the particle from the origin on the interval [0,4][0,4], and state the corresponding time. (e) Interpret the meaning of your answer to part (d) in the context of the particle’s motion, including appropriate units.

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