Notes, summaries, assignments, exams, and problems for Technology

Brakes

Disc Brakes

A disc is connected to an axle. Brake pads apply pressure to the disc via friction.

Band Brakes

A drum is connected to an axle. A flexible band applies pressure to the outside of the drum.

Drum Brakes

A drum is connected to the axle. A pair of brake shoes apply pressure to the inside of the drum via friction.

Energy Absorption and Dissipation

Springs

Springs are devices that, thanks to the elasticity of their materials and their shape, can absorb energy when force is applied. This energy can then be dissipated in a controlled way. Depending on the type of external force applied, springs work in different ways:

• Compression: Pushing on the spring makes it shorter (e.g., a sofa).
• Traction: Pulling on the spring makes it longer (e.g., a

Material Classification

Natural Materials

These materials are obtained directly from nature, such as:

• Wood
• Coal
• Metal
• Stone

Artificial Materials

These materials are derived from natural materials through processing, such as:

• Glass
• Paper
• Cement

Synthetic Materials

These materials are created through chemical reactions involving artificial materials, such as:

• Plastics

Material Types and Their Properties

Ceramics

Ceramics exhibit the following properties:

• Fragility
• Low thermal conductivity
• Low electrical conductivity
• Hardness
• Brittleness

Metallic Materials

Metals possess these characteristics:

• High electrical and thermal conductivity
• Resistance
• Ductility
• Malleability
• Ability to form alloys with other elements to enhance properties

Plastics/Polyesters

Plastics and polyesters... Continue reading "Understanding Materials: Properties, Types, and Treatments" »

Computer Basics

A computer is a device that processes data according to a set of instructions known as a program.

Hardware and Software

Hardware: The equipment. Software: The programs and data.

Operating System

The operating system is a special set of programs that provides an interface for the user and allows application programs to communicate with the hardware.

Application Programs

Application programs include:

• Word processors (for creating and editing texts)
• Spreadsheets (for calculating mathematical formulae)
• Databases (for storing data in a way that allows the data to be sorted and searched)

Antivirus Programs

Antivirus programs are used to detect and remove viruses (harmful programs that can reproduce themselves and attach themselves to other programs)... Continue reading "Computer Hardware, Software, and Peripherals: A Comprehensive Look" »

• Unit 7

Electronic Components Guide

Basic Components

Battery

A device consisting of one or more electrochemical cells with external connections for powering electrical devices. Power supply.

Light Bulb

An electric light with a wire filament heated until it glows. The filament is enclosed in a bulb to protect it from oxidation. Load device.

Motor

An electrical machine that converts electrical energy into mechanical energy. Load device.

Buzzer

A device that makes a buzzing noise and is used for signaling. May be mechanical, electromechanical, or piezoelectric. Load device.

Semiconductor Components

Diode

Formed by the union of two semiconductors: P-type (anode) and N-type (cathode). Load device.

Light-Emitting Diode (LED)

An electronic device that emits light when... Continue reading "Electronic Components Guide: Types, Functions & Applications" »

• Limited: kept within a particular size
• Potential: possible when the necessary conditions exist
• Excessive: more than is necessary
• Peer pressure: the influence of people who are similar age
• Disadvantaged: in a situation in which you are less likely to succeed than others
• Irritable: becoming annoyed very easily
• Expose: to remove what is covering something that is very large
• Awash: having an amount of something that is very large
• Artificial: not natural
• Upgrade: to improve something so that it is of a higher quality
• Zip a file: to reduce the size of a computer file
• Save: to make sure that a computer keeps information
• Browse the internet: to look at information on the internet
• Plug sth in: to connect a piece of electrical equipment to an electricity supply
• Sync

STEEL

Scrap can be sorted easily using magnetism. If the metal is galvanized (coated with zinc), the zinc is fully recyclable. If it is stainless steel, other metals mixed with the iron, such as chromium and nickel, can also be recovered and recycled.

GLASS

Sorting is critical, as there are key differences between the clear and colored material used in bottles and jars, and the high-grade material used in engineering applications, which contains traces of metals.

COPPER

Scarcity makes recycling especially desirable and justifies the cost of removing insulation from electric wires, which are a major source of scrap. Pure metal can also be recovered from alloys derived from it, notably brass (which also contains quantities of zinc and often lead)... Continue reading "Benefits of Recycling Different Materials and Water Intoxication Symptoms" »

User mode

Switch>

Enter Privilege mode

Switch>enable

Privileged mode

Switch#

Enter configuration mode

Switch#configure terminal

Global Config mode

Switch(config)#

Enter Interface mode

Switch(config)#interface fa0/1

Interface mode

Switch(config-if)

Return to global configuration

Switch(config-if)exit

Exit Global Config mode

Switch(config)#exit

Return to use mode

Switch#disable

Logout

Switch>exit

Keyboard Shortcuts

• Recall Previous command: Up arrow or p
• Recall Next command: Down arrow or n
• Beginning of command: a
• End of command: e
• Delete input: d
• Exit Configuration Mode: z
• Complete command: TAB

Device Configuration

Configure device system name: Switch(config)#hostname sw1

Sets the encrypted enable password: Switch(config)#enable secret cisco

Sets the unencrypted... Continue reading "Cisco Switch and Router Configuration Commands" »

Robots: Types and Characteristics

Androids

Androids are robots designed with human-like features, including realistic skin and sensors that enable them to respond to touch.

Cyborgs

Cyborgs are beings that combine both biological and artificial components.

Robot Components

Motors

Motors convert energy into mechanical motion, enabling robots to move.

Sensors

Sensors receive analog signals and convert them into digital data for processing.

• Temperature sensor
• Pressure sensor
• Touch sensor

Microphones

Microphones allow robots to collect, process, and record sounds, acting as their"ears"

Robot Output

Claws

Robots with claws are programmed to carry objects, often used in factories or junkyards.

Wheels

Robots with wheels can travel various distances under different conditions.... Continue reading "Robots: Types, Components, and Functions" »