Date Class Name Chapter 11 Motion 9. Is the following sentence true or false? When the final velocity is less than the initial velocity of an object, the acceleration is negative. 10. A skateboarder begins down a ramp at a speed of 1.0 m/s. After 3 seconds, her speed has increased to 4.0 m/s. Calculate her acceleration. a. 1.0 m/s b. 3.0 m/$2 c. 5.0 m/ s2 d. 9.8 m/s Graphs of Accelerated Motion (pages 346-348) 11. A speed-time graph in which the displayed data forms a straight line is an example of a(n) For questions 12 through 15, refer to the graphs below. Acceleration Graph A Acceleration Graph B. 20 16 12 Speed (m/s) Speed (m/s) CO N W . 4 O 2 5 10 15 20 Time (s) Time (s) 12. Graph A represents the motion of a downhill skier. How fast was the skier moving after traveling down the hill for 2.5 seconds? 13. In which graph does an object move at constant speed during the first 4 seconds? 14. Graph B represents the motion of a mountain biker. What is the biker's speed at times of 10 s and 20 s? - 15. Determine the acceleration of the mountain biker during the 10 second to 20 second time period. Show your work. 16. The plotted data points representing acceleration in a distance-time graph form a(n) Instantaneous Acceleration (page 348) 17. The measure of how fast a velocity is changing at a specific instant is known as 127 Phucical Srionce Reading and Study Workbook . Chapter 11