Refer to Concept Simulation 2.4 for help in visualizing this problem graphically. A cart is driven by a large propeller or fan, which can accelerate or decelerate the cart. The cart starts out at the position x = 0m, with an initial velocity of +6.5 m/s and a constant acceleration due to the fan. The direction to the right is positive. The cart reaches a maximum position of x = +11.9 m, where it begins to travel in the negative direction. Find the acceleration of the cart. Number i Units A dynamite blast at a quarry launches a rock straight upward, and 2.1 s later it is rising at a rate of 19 m/s. Assuming air resistance has no effect on the rock, calculate its speed (a) at launch and (b) 4.8s after launch. (a)Number i Units (b)Number Units For each of the three pairs of positions listed in the following table, determine the magnitude and direction (positive or negative) of the displacement Initial position Xo Final position x (a) +2.3 m +6.5m (b) +6.lm +2.3m (c) -3.3 m +7.0m (a) Displacement = Number i Units