The diagram below shows the graph of the velocity in ft/sec for a particle moving along the line x=4. Respond the following questions

8 . The diagram below shows the graph of the velocity in fu/sec for a particle moving along the line x = 4. (10 points possible-2 points each) 2- 4 a. During which time interval is the particle: (i) moving upward? (ii) moving downward? (iii) at rest? b. State the acceleration of the particle at the specified times. Include units. (i) t= 0.75 (ii) t = 4.2