This document discusses simple and complex machines, electricity, and important inventions. It begins by defining simple machines like levers, pulleys, wheels, and inclined planes. A complex machine is made of two or more simple machines, like a computer. The document then explains how computers work by taking in input, storing memory, processing data, and outputting information. It also discusses how computers connect to the internet and how they are used to create documents. Next, the document defines electricity, charged objects, static electricity, and electric current. It explains electric circuits and how electricity is generated and distributed. Finally, it briefly profiles some important inventions like the light bulb, television, telephone, and steam engine.

1. MACHINES,
ELECTRICITY
AND
INVENTIONS
UNIT 6

2. 1. SIMPLE MACHINES
Simple machines are made up of one or two parts.
LEVERS
It´s a rigid bar that
turns on a fixed point
called the fulcrum.
PULLEYS
It´s a wheel with an
axle in the centre and
a rope that runs
around the outside.
WHEEL
It´s a disc with an
axle in the centre.
INCLINED PLANES
A ramp or wedge is an
inclined plane that we
use to go up and down.
VIDEO: PulleysVIDEO: Inclined planes VIDEO: Wheels VIDEO: Levers

3. Types of levers
VIDEO

4. A complex machine is the combination of two or more simple machines. A computer is a complex machine.
A computer is an electronic
machine that processes
information. A computer
carries out four main functions:
Input: We use the keyboard
and mouse of the computer to
give data to the computer.
Memory: the computer stores
the data it receives on a hard drive.
Processing: the computer also contains a processor, or Central Processing Unit (CPU). It is a microchip.
Output: the computer has a screen and speakers.
2. COMPLEX MACHINES: THE COMPUTER

5. USING THE INTERNET
The Internet is a computer network that
let’s people all over the world communicate
with each other.
To use the Internet, you need a browser
and an Internet connection. To search
information we have to type keywords into
the browser.
Computers can connect to the Internet
using a cable or by wifi.
HOW DO WE USE A COMPUTER?
CREATING DOCUMENTS OR
SLIDESHOWS
Computers can also be used to create
texts or slideshows.
We need a word-processing program, such
as Microsoft Word, or a slideshow
program, such as Microsoft Power Point.
It is important to save our work regularly.

6. 3. ELECTRICITY
All matter is made up of atoms. Atoms have a nucleus and subatomic particles.
Electricity studies the presence of stationary or moving charged particles, such as
electrons and protons.

7. An object can be charged or neutral.

8. Electrically charged objects
Objects that are electrically charged exert forces on each other.

9. Static electricity
Static electricity is the movement of electrons between two materials.
Electrons can move between materials when we rub them together.
EXPERIMENT 1. Watch the video and make the experiment.

10. Electric current is the movement, or flow,
of electrons between atoms.
4. ELECTRIC CURRENT

11. ELECTRIC ENERGY
Electricity can be generated in power plants. Then it is distributed wherever we need.
We use machines to transform electric energy into other types of energy.

12. An electric circuit is a closed circle. Electricity will only flow if the circuit
is closed.
Electric circuits can be found in every machine that uses electricity.
Types of circuits
5. ELECTRIC CIRCUITS

13. We use symbols to represent the components of an electrical circuit.

14. THOMAS ALVA EDISON – THE LIGHT BULB - 1879 VIDEO THOMAS EDISON
JOHN LOGIE BAIRD – THE TELEVISION – 1925
ALEXANDER GRAHAM BELL – THE TELEPHONE – 1876 VIDEO ALEXANDER GRAHAM BELL
JAMES WATT – THE STEAM ENGINE – 1765 VIDEO: HOW DOES THE STEAM ENGINE WORK?
6. INVENTIONS AND IMPORTANT
MACHINES