Greg walks on a straight road from his home to a convenience store 3.0 km away with a speed of 6.0 km/h. On reaching the store he finds that the store is closed, he instantly turns around and walks back with a speed of 9.0 km/h. Round your final answers to 2 significant figures. a. What is the magnitude of average velocity and average speed of Greg over the first 30 mins of his travel?

B. Find the magnitude of Greg’s average velocity and speed in the time from 0 to 50 minutes

C. Calculate the magnitude of the average velocity and speed in the first 40 minutes (between 0 and 40 mins) of the walk?