12. Draw a position-vs-time graph for an object whose velocity-vs-time graph is shown below. The object starts at the origin. If you think it might be hard to tell what you are drawing, write the word 'linear' or 'curved' above each segment. 13. A ball is being twirled around in a vertical circle on the end of a string. How does the size of the tension force on the ball compare to the size of the gravity force on the ball when the ball is at the bottom of Its path? a) the tension force is greater than the gravity force. b) the tension force is the same size as the gravity force. c) the tension force is smaller than the gravity force. 14. How many forces in total act on the ball in the preceding problem when it is at the bottom