9. A person is pushing a 5 kg block, initially at rest, across a friction-free horizontal surface with a constant horizontal force of 20N. The block is located at the origin when the person starts to push. They push for 4 seconds, then let go and the block continues to slide across the surface. What is the position of the block at t=9 seconds? 10. On your answer grid, neatly, sketch a position-vs-time graph for the block in the previous problem. I will be grading you only on the shape of your graph, so you don't need numbers on the axes but if you think it might be hard to tell whether what you are drawing is curved or linear, write the word 'curved' or 'linear' above each segment. 11. On your answer grid, neatly draw a velocity-vs-time graph for a ball that is thrown straight up into the air, with t=0 being just after the ball is released. End your graph when the ball gets back to the height at which it left the hand.