please help with these

13. The graph of f "(m) on the interval [5, 5] is shown below. On which of the following intervals is the graph of f (w) concave down? Graph of f" O (4, 1) O (0.5] O [5, 2) 0 (0,3) 0 [5, 4) 14. The velocity (1; (in of a particle was measured at certain times (t) and recorded in the table below. What is the average acceleration of the particle on the interval [3,11]? 13 0 3 5 9 11 w) 8 15 11 0 7