1. (6 marks) Samir is biking along a straight path, starting in the 3(3) 9 northbound directiOn. Here is a graph that shows ' 3 Samir's position 3 (in kilometers) at time t (in hours). 7 6 (a) What is Samir's average velocity in the time from 5 t = 1 to t = 4? 4 3 2 (b) What is Samir's velocity at time t = 7.5 and in what direction is he moving? (o) By looking at the graph, determine whether Samir is speeding up or slowing down at time t = 6.1. Explain your reasoning