1. Do Now!

2. Last lesson Measuring speeds in a practical situation Composing a formal letter to the police Evening all!

3. A reminder Average speed = distance travelled time taken S t d x

4. Number plate Distance (m) Time (s)Speed (m/s)Speed (mph) Speeding?

5. What to do now Calculate the speeds Convert to mph by multiplying by 2.24 Homework is to write a letter to the police informing them of which cars broke the speed limit and describing in detail how we measured the speeds (due Monday 1 st Feb)

6. Speed Investigation Careful! Reliable? Sensible!

7. Next lesson! Interpreting distance-time and speed-time graphs

8. Distance against time graphs distance time

9. No movement? distance time

10. No movement distance time

11. Constant speed? distance time

12. Constant speed distance time

13. Constant speed distance time The gradient of this graph gives the speed

14. Constant speed distance time How would the graph look different for a faster constant speed?

15. Constant speed distance time fast

16. Constant speed distance time fast How would the graph look different for a slower constant speed?

17. Constant speed distance time fast slow

18. Getting faster? (accelerating) distance time

19. Getting faster distance time

20. Examples distance time

21. A car accelerating from stop and then hitting a wall distance time

22. A car accelerating from stop and then hitting a wall distance time

23. Speed against time graphs speed time

24. No movement? speed time

25. No movement speed time

26. Constant speed? speed time

27. Constant speed speed time

28. Constant speed speed time How would the graph look different for a faster constant speed?

29. Constant speed speed time fast

30. Constant speed speed time fast How would the graph look different for a slower constant speed?

31. Constant speed speed time fast slow

32. Getting faster? (accelerating) speed time

33. Getting faster? (accelerating) speed time Constant acceleration

34. Getting faster? (accelerating) speed time The area under the graph gives the distance travelled

35. Example: speed time

36. A dog falling from a tall building (no air resistance) speed time

37. A dog falling from a tall building (no air resistance) speed time

38. A dog falling from a tall building (no air resistance) speed time Area = height of building

39. Be careful! distance time speed time

40. No movement distance time speed time

41. Constant speed distance time speed time Area = distance travelled

42. Constant acceleration distance time speed time Area = distance travelled