1. Do now! Can you read each others “Density questions” that you did for homework?

2. This lesson – 2.4 Pressure Relate (without calculation) pressure to force and area. Recall and use the equation P = F/A

3. Oh no! YouTube - falling through ice YouTube - Jason Falls Through Ice

4. Spread the force over a greater area

5. Camels

6. Snow shoes Tom

7. Caterpillar tracks

8. House foundations

9. My sofa!

10. Sharp?

11. I had a dream

12. Death?

13. Drawing pins

14. Pressure Pressure = Force Area N/m 2 or Pa N m2m2

15. Pressure Pressure = Force Area N/m 2 or Pa N m2m2 F AP x Can you copy this please?

16. An example A woman of weight 600N has a total shoe area of 150 cm 2 and a man of weight 750 N has a total shoe area of 360 cm 2. What is the pressure beneath their feet?

17. An example A woman of weight 600N has a total shoe area of 150 cm 2 and a man of weight 750 N has a total shoe area of 360 cm 2. What is the pressure beneath their feet? Angelina pressure = force/area = 600/150 = 4 N/cm 2 Brad pressure = force/area = 750/360 = 2.1 N/cm 2

18. Bunny Suicides involving pressure

22. Calculating your own pressure Can you do the calculations carefully and neatly on the graph paper to show your pressure (don’t forget you have two feet!) and stick it in your book

23. Pressure under a car

26. Mass = 2000kg Weight = mg = 2000x10 = 20000N Area = ? Pressure = ?

27. U571 YouTube - Ocean Odyssey - Ocean PressureYouTube - Ocean Odyssey - Ocean Pressure YouTube - Styrofoam cup vs. deep sea YouTube - U-571 Trailer

28. Fluid pressure acts in all directions Copy!

29. Pressure and depth Pressure increases with depth (P = ρgh)

30. Let’s try some questions! Page 63, questions 1 to 4.

31. That’s it! Let’s remind ourselves of what we have done in this unit.

32. Newton’s 1 st Law If there is no resultant force acting on an object, it will move with constant velocity. (Note the constant velocity could be zero). Remember?

33. Newton’s 1 st law If there are no forces, or the forces are balanced – constant velocity NO RESULTANT FORCE Pushing force friction

34. Newton’s 2 nd law There is a mathematical relationship between the resultant force and acceleration. Resultant force (N) = mass (kg) x acceleration (m/s 2 ) F = ma

35. An example What will be Mr Porter’s acceleration? Pushing force (100 N) Friction (60 N) Mass of Mr Porter and bike = 100 kg

36. An example Resultant force = 100 – 60 = 40 N F R = ma 40 = 100a a = 0.4 m/s 2 Pushing force (100 N) Friction (60 N) Mass of Mr Porter and bike = 100 kg