1. Supports TUTORIAL 3 to answer just click on the button or image related to the answer

2. Question 1 how many reactions can be produced by a fixed support? What are they? 2 – horizontal, vertical a 3 – horizontal, vertical, moment b more c

3. Question 2 1 - vertical a how many reactions can be produced by a simple support? What are they? 2 – horizontal, vertical b 3 – horizontal, vertical & moment c

4. Question 3 1 - vertical a how many reactions can be produced by a roller support? (pinned at top) 2 – vertical, horizontal b 3 – vertical, horizontal, moment c

5. Question 4 1 - vertical a how many reactions can be produced by a pinned (hinged) support? What are they? 2 – vertical, horizontal b 3 – vertical, horizontal, moment c

6. Question 5 1 - vertical a 2 – vertical, horizontal b 3 – vertical, horizontal, moment c how many reactions can be produced by the structural system shown? What are they

7. Question 6 What does structurally determinate mean ? structure has 3 reactions a can use just the 3 equations of static equilibrium to calculate reactions c a and b d b reactions cannot be calculated using the 3 equations of static equilibrium alone a and c e

8. how many reactions can be produced by the structural system shown? Draw them Question 7a 1 a 2 b 3 c 4 d simple support

9. Question 7b is the system? statically determinate a statically indeterminate b a mechanism c simple support

10. how many reactions can be produced by the structural system shown? Draw them Question 8a 1 a 2 b 3 c 4 d pin joints

11. Question 8b is the system? statically determinate a a mechanism c pin joints statically indeterminate b

12. how many reactions can be produced by the structural system shown? Draw them Question 9a 2 a 4 b 6 c simply supported

13. Question 9b is the system? statically determinate a statically indeterminate b a mechanism c simply supported

14. how many reactions can be produced by the structural system shown? Draw them Question 10a 2 a 3 b 4 c 6 d

15. Question 10b is the system? statically determinate a statically indeterminate b a mechanism c

16. how many reactions can be produced by the structural system shown? Draw them Question 11a 1 a 2 b 3 c more d

17. Question 11b is the system? statically determinate a statically indeterminate b a mechanism c

18. next question enough ! H V M a fixed support can have 3 reactions horizontal H, Vertical V and moment M

19. let me try again let me out of here try harder we are talking about a fixed support

20. let me try again let me out of here we are talking about just one support

21. next question enough ! a simple support can only have 1 reaction - just a vertical, V. If you apply a force horizontally - it moves V

22. let me try again let me out of here we are talking about a simple support (think what happens if you apply a force horizontally)

23. let me try again let me out of here we are talking about a simple support (think what happens if you apply a force horizontally. Think what happens to the ends. Do they go up –i.e. they rotate? If they do then there is no moment reaction)

24. next question enough ! a roller support can only have 1 reaction - just a vertical, V. If you apply a force horizontally - it moves and since it is pinned it can’t produce a moment reaction V

25. let me try again let me out of here we are talking about a roller support (think what happens if you apply a force horizontally what happens if you push someone on roller skates – do they resist?)

26. let me try again let me out of here we are talking about a roller support (think what happens if you apply a force horizontally what happens if you push someone on roller skates – do they resist? Since it is pinned what happens if you apply a force to a hinge – does it rotate or resist? Think of opening a door)

27. next question enough ! a hinged support can only have 2 reactions - a vertical, V. and a horizontal, H It can’t produce a moment reaction V H

28. let me try again let me out of here we are talking about a hinged support (think what happens if you apply a force horizontally can it come off the hinge? What happens if you pull a door?)

29. let me try again let me out of here we are talking about a pinned support (think what happens if you apply a force horizontally can it come off the hinge? What happens if you pull a door? Since it is pinned what happens if you apply a force to a hinge – does it rotate or resist? Think of opening a door)

30. next question enough ! this is a rigid support Remember Question 1? V H V M

31. let me try again let me out of here we are talking about a fixed support (remember Question 1?) Does it pull out of the wall? Does it spin/rotate?

32. That’s it exactly. A statically determinate structure is one that can produce exactly 3 reactions. Statically determinate means just that: You can use the 3 equations of static equilibrium to calculate the reactions next question enough !

33. let me try again let me out of here that’s part of the story what would happen if there were 2 reactions, or 4? think of the word ‘determinate’ – what does that mean?

34. let me try again let me out of here statically determinate what would happen if there were 2 reactions, or 4? think of the word ‘determinate’ – what does that mean?

35. that’s it exactly! next question enough ! 3 reactions for the rigid support (V, H, M) and 1 for the simple support (V) makes 4 altogether simple support

36. let me try again let me out of here THINK !! how many reactions can a cantilever produce? how many reactions can a simple support produce?

37. that’s it exactly! next question enough ! more than 3 reactions makes a system statically indeterminate, meaning that the reactions cannot be determined by the 3 equations of static equilibrium simple support

38. let me try again let me out of here THINK !! how many equations of static equilibrium are here? therefore what make a system statically determinate?

39. let me try again let me out of here THINK !! what makes a mechanism? (when ‘structure’ cannot provide the necessary reactions) how many reactions have we got?

40. that’s it exactly! next question enough ! 2 reactions (V, H) for each pin jointed support makes 4 altogether pin joints

41. let me try again let me out of here THINK !! how many reactions can one pin joint produce? how many pin joints are there?

42. that’s it exactly! next question enough ! more than 3 reactions makes a system statically indeterminate. that means the reactions cannot be determined by the 3 equations of static equilibrium pin joints

43. let me try again let me out of here THINK !! how many equations of static equilibrium are here? therefore what make a system statically determinate?

44. let me try again let me out of here THINK !! what makes a mechanism? (when ‘structure’ cannot provide the necessary reactions) how many reactions have we got?

45. that’s it exactly! next question enough ! 1 reaction (V) for each simple support makes 2 altogether simply supported

46. let me try again let me out of here THINK !! If you push from the side what happens? Does it resist? Is there anything to prevent the ends from rotating? So how many reactions can one simple support produce? how many simple supports are there?

47. that’s it exactly! next question enough ! less than 3 reactions makes a system a mechanism. If you push from the side, the beam will move (slide). This is a mechanism simply supported

48. let me try again let me out of here THINK !! How many reactions do you need to make a system statically determinate? How many reactions do you need to make a system statically indeterminate?

49. that’s it exactly! next question enough ! 3 reactions for each rigid joint (V, H, M) makes 6 altogether

50. let me try again let me out of here THINK !! how many reactions can a rigid support produce? how many rigid supports are there?

51. that’s it exactly! next question enough ! more than 3 reactions makes a system statically indeterminate, meaning that the reactions cannot be determined by just using the 3 equations of static equilibrium

52. let me try again let me out of here THINK !! What makes a system a mechanism? How many reactions do you need to make a system statically determinate? How many reactions do you need to make a system statically indeterminate?

53. that’s it exactly! next question enough ! 2 reactions for the pin joint (V, H) and 1 for the roller (V) makes 3 altogether

54. let me try again let me out of here THINK !! how many reactions can a pin joint produce? how many reactions can a roller support produce? So how many reactions are there in total?

55. that’s it exactly! the END 3 reactions makes a system statically determinate, meaning that the reactions can be determined by just using the 3 equations of static equilibrium

56. let me try again let me out of here THINK !! What makes a system a mechanism? How many reactions do you need to make a system statically determinate? How many reactions do you need to make a system statically indeterminate?