Do Now!

1. Can you put the “Unit 1 CONTENTS” sheet in the front of your folders. There will be a Unit 1 TEST on Friday 25th September, when Mr Porter will also collect in your folders. Do Now!

2. A reminder

3. distance speed time time No movement

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

5. distance speed time time Constant acceleration Gradient = acceleration a = (v-u)/t Area = distance travelled

6. Today’s lesson • Define displacement, velocity, speed and acceleration • Explain the difference between instantaneous and average values of speed, velocity and acceleration

7. Displacement

8. Displacement • Displacement the distance moved in a stated direction (the distance and direction from the starting point). A VECTOR

9. Velocity?

10. Velocity? • Velocity is the rate of change of displacement. Also a VECTOR

11. An interesting example Think of a dog (dead) orbiting the earth with constant speed (in a circle).

12. An interesting example At this point, what is its velocity? velocity?

13. An interesting example velocity

14. An interesting example What is its velocity here? velocity?

15. An interesting example As you can see the velocity has changed as it is now going in another direction. velocity

16. An interesting example We have constant speed but changing velocity. velocity

17. Acceleration?

18. Acceleration? • Acceleration is the rate of change of velocity. Also a VECTOR

19. An interesting example We have constant speed but changing velocity. Of course a changing velocity means it must be accelerating! velocity

20. Average speed/velocity?

21. Average speed/velocity? • Average speed/velocity is change in distance/displacement divided by time taken over a period of time.

22. Instantaneous speed/velocity?

23. Instantaneous speed/velocity? • Instantaneous speed/velocity is the change in distance/displacement divided by time at one particular time.

24. Let’s try some questions! Page 45 questions 1, 2, 3, 4, 5, 8, 10.