1. Structures all around us Chapter 10.1

2. A structure is something made of parts that are put together for a particular purpose. They can be man made or found in nature

3. Man made structures:

4. Taj Mahal- India

5. Great Pyramid- Egypt

6. Great wall of china- china

7. Eiffel tower- France

8. Chrysler building- new york

9. Big ben- England

10. Machu pichu- peru

11. Stonehenge- England

12. Angkor Wat, Cambodia

13. Museo Guggenheim, Spain

14. Bibliotheca Alexandrina, Egypt

15. Imam Mosque, Iran

16. Natural Structures:

20. http://www.youtube.com/watch?v=1IugvemOyZY

21. All structures have at least one main function, which is the task or purpose that the structure is designed to perform. Form is the physical appearance. A structure’s shape and appearance relate to its function. Form relates to Function.

22. Function The main function of a roof is to protect a house from weather conditions.

23. Form We want our structures to look good, don’t we?

24. Chapter 10.2: Forces How would you move a stool? You could:  Push the stool  Pull the stool  Lift the stool

25. Each case involves the application of a force, which is a push or a pull. To lift the stool, you must overcome the downward pull of the earth. Pull is known as gravitation force (gravity) Gravity is a force.

26. Gravity acts differently on objects with different masses. Objects with little mass have weak gravitational pull. Objects with large mass have more of a gravitational pull.

29. Objects that are large and have a lot of mass (such as the earth) can attract other objects from a great distance. Some objects are so small that their gravitational pull is not visible (but it is there) Particle theory: All particles are attracted to each other. Gravity, yo!

30. In most cases, force can only be applied with one object comes into contact with another. The exception is gravity. Gravity can still pull objects (such as a basketball falling to the ground). Magnetic force and electrostatic force also has this ability

32. Forces that push or pull are known as applied forces.

33. Distinguishing between Mass and Weight Mass and weight have different meanings and different units of measurement. Mass: Is the quantity of matter in an object. Can be measured with a scale. Common units are grams (g) and kilograms (kg) Weight: force of Earth’s gravity acting on an object. Measured in newtons (N).

34. Spring scales can measure weight:

35. Mass of an object remains the same anywhere in the universe, but its weight can change.

36. Weight on the Moon is different then weight on Earth.

37. Loads Designers have to consider all the forces when constructing a structure. The force acting on a structure is called a load. Dead load is the weight of the structure itself. Live load is the weight of the object that a structure supports.

39. Dynamic loads are those caused by forces other than the force of gravity. i.e.,: moving water and wind.