The Wonderful World of… TECHNOLOGY
Class Starter Questions What is technology? What is a technical object? Give some examples. What objects are not technical objects? Give some examples. What types of materials are technical objects made of? Take a look at your pencil: Is it a technical object? What materials is it made of? Why were these materials chosen? What happens when there is too much stress on a material?
What IS technology?
What is Technology? Technology is the making, usage, and knowledge of tools, machines, techniques, crafts, systems or methods of organization in order to solve a problem or perform a specific function.
What’s a Technical Object? A man-made object that serves a purpose.
Materials Wood Metal Plastic Stone Ceramic Textile Glass Synthetic materials
Your Pencils (again) Have you ever asked yourself why pencils are never made out of rubber? Or out of glass?
Your Pencils Take a look at your pencils in your hands Is it a technical object? What are the materials it is made of? Why were these materials chosen?
MATERIALS External forces produce various effects inside a material. EXAMPLE: *Consider what would happen if an elephant walked in the room and stepped on your pencil. What would the effect be? EXTERNAL FORCE = Elephant weight EFFECT = pencil being crushed
Different materials react differently to different external forces. A material will undergo a mechanical constraint due to the force.
MECHANICAL CONSTRAINTS “A mechanical constraint describes the stress produced within a material when it is subjected to external forces.” 5 types of constraints: Compression, Tension, Torsion, Bending, Shearing
COMPRESSION: Force that crushes materials
TENSION: Force that stretches materials
TORSION: Force that twists materials
BENDING: Force that bends materials
SHEARING: Force that cuts or tears materials
EXAMPLES: Tension, bending Compression Torsion, compression SHOES: CLICKER: WATER BOTTLE: Compression Torsion, compression
What happens when there is TOO MUCH STRESS on a material? Elastic deformation – Temporary deformation of material. Resumes shape. Plastic deformation – Remains deformed. Fracture – Material ruptures.