SCIENCE 5 - UNIT 9
TECHNOLOGY
(this summary reviews important Science 4
and Science 5 information we need to study)
Ancient inventions: wheel, abacus, horse-drawn cart, plough, gears...
Previous to electricity inventions: printing press, steam engine, typewriter...
Age of electricity's inventions: light bulb, telephone, plane...
Age of electronics, robotics, and ICT's newest inventions: the latest 21st-century gadgets, complex electronic inventions, microchips, robots, computers...
Classification of machines by the energy source they need to work.
Machines can make life easier for us, but they need energy to work.
Bicycles, baby strollers and wind-up alarm clock need energy from people.
DVD players, TV players, washing machines, dishwashers, toasters, etc. need electricity supply. We use a plug and socket to connect.
Cars and motorbikes need fuels (petrol, diesel...) or powerful batteries.
TV remote controls need little batteries.
Old mills need wind (moving air) or moving water (water wheels).
Classification of machines by their function.
- Mechanical machines: with a motor (from electricity) or engine (from fuel) they produce movement (kinetic energy). E.g.: cars, motorcycles, electric toothbrushes, washing machines, vacuum cleaners, dishwashers, electric toothbrushes...
- Thermal machines: they make things hot or cold. E.g.: air-conditioners, heaters, radiators, hair dryers, refrigerators, freezers, electric ovens...
- Information-processing machines: they are used to communicate and to make calculations. E.g.: computers, tablets, mobile phones, digital cameras, calculators...
Classification of machines by their complexity (book: Many machines in one)
A machine is something that helps us do work with less effort. There are two kinds of machines:
Simple machines have few or no moving parts. We put simple machines together to make complex machines.
Complex machines use two or more simple machines. Many complex machines at home need electricity to work.
SIMPLE MACHINES
Simple machines have few or no moving parts. They reduce the amount of force we need to apply to complete a task. These are the different types of simple machines:
A wedge has one or more slanting surface. When we push down on the flat part of the wedge, we can cut things or push things apart more easily.
An inclined plane is made up of a flat, slanting surface. It is easier to push an object up an inclined plane than to lift it vertically.
A pulley has a rope and a wheel and axle. When we pull down on the rope, we lift the object that is attached to it. Pulling the rope is easier than lifting an object using our body. E.g.: car brakes, lifts (elevators), bicycle gears...
A wheel and axle has a wheel or wheels which revolve around an axle. We use a wheel and axle to move things across the ground more easily. E.g.: land transport: trains, cars, motorbikes, lorries, vans, ...
A screw is an inclined plane that goes around a cylinder or cone. We use screws to hold things together or lift objects. Turning a screw is easier than pushing the screw directly. E.g.: They are all around: electrical appliances, transport, computers, bikes, but also simple objects like jars.
A lever is a rigid bar which is placed on a support called a fulcrum. Levers can be classified by the position of the three key elements: the fulcrum (F), the load (L) and the place where the effort or force takes place (E). It's easier to lift an object when we use a lever and fulcrum. E.g.: a car's gearstick, a bicycle's pedals and brake levers, a stapler...
NOTE: Advanced machines are made up of many simple and complex machines. Sometimes they have parts like gears, engines and motors, etc.
- Gears: they are wheels with teeth that fit together. When one wheel turns the other one turns too, but in the opposite direction. E.g. cars, motorbikes, bicycles, windmills, clocks and watches, toys with motors.
- Engines and motors: it is the part of the machine which produces movement. An engine needs fuel to work, whereas a motor runs on electricity.
TECHNOLOGY INFLUENCES OUR LIVES
SAFER AND MORE COMFORTABLE HOMES:
- Smart phones: to write texts, watch films, listen to music, find information on the Internet, send emails, read newspapers and books, do the shopping, take photos and make videos... They are small PCs (personal computers).
- Domestic chores with machines: dishwashers, washing machines, microwave ovens, food processors, vacuum cleaners...
- Food storage: freezers, refrigerators...
- Heating and air-conditioning appliances to control the temperature.
- Energy-saving light bulbs.
- Sanitation: drinking water, WC toilets, sinks, bath tubs...
- Communication: e- mails, video-conference, text messages, telephones...
- Electricity and Internet connectivity for many of the appliances listed above.
INDUSTRIAL CHANGES (FACTORIES):
- Companies are developing environmentally friendly machines and materials.
- Governments can also create laws to control industry.
- Awareness of air and water pollution, soil and radioactive contamination.
- Biodegradable products.
EDUCATION
- Computers with Internet connectivity, interactive whiteboards, tablets, e-books...
TRANSPORT
- Travel time has been reduced (faster transportation).
- Vehicles are safer.
- Use of alternative energy sources such as eco-fuel, bio-diesel or solar energy.
FREE TIME
- Spectacular special effects on films.
- Computer-generated cartoons.
- Films in 3D (three dimensions).
- Museums with interactive activities.
HEALTH (technology in hospitals)
* X-rays, CT scans and ultrasound devices to detect diseases (diagnosis).
* Devices to measure the level of glucose in blood (blood and urine tests).
* Devices that measure blood pressure.
Keep safe!
- Machines help us but they can become dangerous.
- We must use them responsibly, with caution.
- Scissors and knives must be carried away from the body, with the sharp parts pointing down.
- Never run with a tool in your hand.
- We need to wear appropriate clothing: make sure your clothes can’t get caught up in the moving parts. (before riding a bike: check your shoelaces, don't wear a scarf, and the brakes, gears and lights working properly). Roll up long sleeves and tie long hair back too.
- Wear safety goggles when there is the possibility that something could enter your eyes as you are working.
- Be especially careful when using electrical appliances (electric shock, which can cause burns to your body, or even stop your heart).
* Don’t touch power points. Never use a knife to remove a slice of bread from the toaster.
* Never touch electrical appliances or cables near a bathtub or swimming pool or if you are wet (hairdryers). Water is a electrical conductor.
* Don’t plug too many appliances into one power point.
System overload can cause a fire.
* Use power boards not double adaptors.
* Unplug appliances by pulling on the plug (NOT the cord).
* Tell your parents if the plastic protection around a cable is damaged.
* Watch out for danger signs: stay away and tell an adult!
