A particle moves back and forth along a straight line. Its position, in meters, relative to the origin, at any time , in seconds, is given by ()=2372+4+1. Find the following and round your answer to the nearest tenth, if necessary. (8 marks) a. The average velocity between 2 and 6 seconds. b. The velocity when the particle is at the origin. c. When the particle is slowing down. d. The total distance travelled after 8 seconds.