Distance and Displacement

1. Ch. 11. 1 Distance and Displacement

3. Frame of Reference • Helps describe motion accurately and completely • A system of objects NOT moving with respect to one another • Relative Motion • Movement in relation to a frame of reference • Ex: Train • Platform- people on train are moving • In train- people are not moving

4. Measuring Distance • Distance= the length of a path between 2 points • SI Unit- meter kilometer- large distance centimeter- small distance

5. Measuring Displacement • Displacement= direction from start point and length of a straight line from start to end point • Travel 5 blocks north of the bus stop

6. Combining Displacements • Vector= quantity that has magnitude and direction • Magnitude= size, length, or amount • Shown as arrows on maps/graphs • Add displacements by adding vectors

7. Combining Displacements -Straight Lines • Add magnitudes if • 2 vectors have same direction • Ex: 1st car magnitude= 4km (pg 330) 2nd car magnitude= 2 km Both traveling same direction = ____ km displacement Opposite traveling direction = ____km displacement

8. Combining Displacements - Not straight lines • Add total distance • Draw resultant vector • Vector sum of 2 or more vectors • Also displacement • Pg 331- Walked 7 blocks Displacement= 5 blocks NE

9. *Integrating Math -Pythagorean theorem • a2 + b2 = c2 • Find distance traveled and displacement

10. Ch. 11.2 Speed and Velocity

12. Speed • Speed= the ratio of the distance an object moves to amount of time the object moves • SI Unit- meters per second m/s km/h • 2 Types of Speed

13. 2 Types of Speed Average Speed Instantaneous speed Speed at a particular instant Can tell you how long your trip will take Speedometers • Speed computed for entire duration of trip • v = d t

14. Calculating Speed Practice While traveling on vacation, you travel 35 km in 0.4 hours, then 53 km in 0.6 hours. What is your average speed? 1. Given Info Total distance: Total time: 2. Solve need speed 3. Plug and chug 4. Check

15. Math Practice pg 333 1. 2.

16. Graphing Motion • Slope of a line on a distance-time graph is speed • Pg 334 • Calculate slope of • A= • B= • C=

17. Velocity • Velocity= the speed and direction in which an object is moving • Description of BOTH speed and direction • Vector • Change in velocity • Change in speed, direction or both

18. Race car traveling 120 km/h Speed, direction, velocity?

19. Combining Velocity • 2 or more velocities added by vectors • River= 5 km/h • Boat= 12 km/h • Total velocity= • pg. 337 • River= 5 km/h • Boat= 12 km/h • Total Velocity=

20. Ch. 11.3 Acceleration

22. Acceleration • The rate at which velocity changes • Changes in speed, direction or both • vector

23. Acceleration Change in speed Change in direction Speed can be constant, but a change in direction yields acceleration • Increase or decrease in speed • Free fall- movement of object toward Earth due to gravity(9.8m/s2) • SI unit- m/s2

24. Acceleration Change in speed & direction Constant acceleration Steady change in velocity

25. Calculating Acceleration

26. Acceleration Practice A ball rolls down a ramp, starting from rest. After 2 seconds its velocity is 6m/s. What is the acceleration of the ball? • Given Info Time- Vi- Vf- 2. Plug and Chug acceleration-? 3. Check

27. Math Practice pg 346 • 1. • 3. • 2. • 4.

28. Graphs of Acceleration • Slope of speed-time graphs is acceleration • Change in speed divided by change in time

29. Graphs speed-time graph Distance-time graph Nonlinear graphs • Linear graphs

30. Instantaneous Acceleration • How fast a velocity is changing at a specific instant

31. Review

32. Review Motion acceleration displacement Change in speed direction