Sec2.3: Problem 21 (1 point) Book Problem 43 A particle moves along a straight line and its position at time t is given by 3(t) 2 2t3 ~ 24t2 + 72:: where sis measured in feet and tin seconds. . a) Find the velocity (in msec) oflhe particle at time t = 0: b) The particle stops moving twice. once when t : A and again when t : B where A