일반물리학 1 — Motion Along a Straight Line: Problem 15

15 The displacement of a particle moving along an x axis is given by \(x = 18t + 5.0t^2\), where \(x\) is in meters and \(t\) is in seconds. Calculate (a) the instantaneous velocity at \(t = 2.0 \text{ s}\) and (b) the average velocity between \(t = 2.0 \text{ s}\) and \(t = 3.0 \text{ s}\).