Science 6º
domingo, 8 de febrero de 2015
MACHINES
A
machine is something that allows us to do work with less effort. We can
classify machines depending on the function they do. (Simple machines and
complex machines)
Simple machines: They have few or no moving parts and we use our own
energy to make it work.
Complex machines: It´s made of two or more simple machines and it
often needs electricity to work.
THE SIX SIMPLE MACHINES
1. A lever and fulcrum:
This machine is a rigid bar, which turns on a support called a fulcrum.
2. A wheel and axle: we
use a wheel and axles to move things across the ground more easily.
3. A screw: We use a
screw to hold thing together or lift objects.
4. An inclined plane:
It`s made up of a flat, slanting surface. It´s easier to push an object up an
inclined plane than to lift it vertically.
5. A pulley: This
machine has a wheel and axle and a rope. Pulling the rope is easier than
lifting an object using our body.
6. A wedge: We can cut
things or push things apart more easily.
FORCES
A force is a push or a pull that acts on an object. Forces can make
an object move, change direction, slow down or accelerate and change shape.
There are different types of forces:
· 1. FRICTION: It`s the force that exist when two
objects rub against each other. This force can slow down or stop a moving
object.
· 2. GRAVITY: It is a force
which attracts all objects to each other. The Earth`s gravity stops everything
moving into outer space.
We can classify machines by the energy source they use:
-Some machines need energy from people to work.
- Some machines need Energy from wind or water to work.
-Some machines need fuel such as petrol.
-Some machines need electricity to work.
We can also classify machines by their function: They can be
mechanical , thermal or they can process information.
1. Mechanical machines have a motor or an engine which transforms
electricity or fuel into kinetic energy making things move.
2. Thermal machines make things hot or cold.
3.
Information-processing machines they are used to communicate and to make
calculations.
COMPLEX MACHINES
1.
Casing: The casing is the outer part of the machine. It protects the machine
from damage and dust
2.
Operational
parts: The operational parts are the individual component
of the machine.
3.
A mechanism: is a group of components which work together to perform a specific function.
4.
An engine: Is the part of the machine that produce movement.
5.
Microchips: Microchips have the smallest electric circuit.
COMPUTERS
Today we can communicate
almost instantaneously with almost anywhere in the world. Hundreds of communication
satellites orbiting the Earth.
The invention of
the computer has help other many technologies.
An important
development in the technology was the microchip. A microchip contain microscopic
circuits witch allow the computer process information more quickly.

MACHINES
A
machine is something that allows us to do work with less effort. We can
classify machines depending on the function they do. (Simple machines and
complex machines)
Simple machines: They have few or no moving parts and we use our own
energy to make it work.
Complex machines: It´s made of two or more simple machines and it
often needs electricity to work.
THE SIX SIMPLE MACHINES
1. A lever and fulcrum:
This machine is a rigid bar, which turns on a support called a fulcrum.
2. A wheel and axle: we
use a wheel and axles to move things across the ground more easily.
3. A screw: We use a
screw to hold thing together or lift objects.
4. An inclined plane:
It`s made up of a flat, slanting surface. It´s easier to push an object up an
inclined plane than to lift it vertically.
5. A pulley: This
machine has a wheel and axle and a rope. Pulling the rope is easier than
lifting an object using our body.
6. A wedge: We can cut
things or push things apart more easily.
FORCES
A force is a push or a pull that acts on an object. Forces can make
an object move, change direction, slow down or accelerate and change shape.
There are different types of forces:
· 1. FRICTION: It`s the force that exist when two
objects rub against each other. This force can slow down or stop a moving
object.
· 2. GRAVITY: It is a force
which attracts all objects to each other. The Earth`s gravity stops everything
moving into outer space.
We can classify machines by the energy source they use:
-Some machines need energy from people to work.
- Some machines need Energy from wind or water to work.
-Some machines need fuel such as petrol.
-Some machines need electricity to work.
We can also classify machines by their function: They can be
mechanical , thermal or they can process information.
1. Mechanical machines have a motor or an engine which transforms
electricity or fuel into kinetic energy making things move.
2. Thermal machines make things hot or cold.
3.
Information-processing machines they are used to communicate and to make
calculations.
COMPLEX MACHINES
1.
Casing: The casing is the outer part of the machine. It protects the machine
from damage and dust
2.
Operational
parts: The operational parts are the individual component
of the machine.
3.
A mechanism: is a group of components which work together to perform a specific function.
4.
An engine: Is the part of the machine that produce movement.
5.
Microchips: Microchips have the smallest electric circuit.
COMPUTERS
Today we can communicate
almost instantaneously with almost anywhere in the world. Hundreds of communication
satellites orbiting the Earth.
The invention of
the computer has help other many technologies.
An important
development in the technology was the microchip. A microchip contain microscopic
circuits witch allow the computer process information more quickly.

jueves, 22 de enero de 2015
ELECTRICITY AND MAGNETISM
CURRENT ELECTRICITY
When an electrical charge
moves in an electrical conductor we have current electricity. (Metals, such as
copper)
An electric circuit is made up
of different parts which are all connected together.
1.
-Generators: These supply the electricity
2.
Conductors: These are metals wires, which are covered in
insulating material and let the electricity flow.
3.
Electrical
components: These transform electricity
into another form of energy light bulb transform into light.
4.
Switches: These open and close the electric circuit.
MAGNETISM
Magnetism is the ability to
attract some metals. Magnets can be natural or man-made (Magnetite it`s an
example of a natural magnet).All magnets have two poles. These are called the
North Pole and the South Pole.
When two magnets touch at the
poles, one of two things can happen:
·
If we put
the same poles together, the magnets will repel each other.
·
If we put
opposite poles together, the magnets will attract each other.
ENERGY SOURCES
Energy sources provide us with
energy. There are two types of energy sources.
1.
Non-renewable
energy sources. They can`t be replaced in our
life time. Some example are: uranium used in nuclear power station, oil, coal,
gas…
2.
Renewable
energy sources. They can be replaced and
never run out. Some examples are: Biomass, organic materials, sun light, wind,
water, geothermal…
HUMAN BODY
TYPES OF JOINTS:
Fixed joints: This joints don`t move.
Semi-flexible joints: This joints allow a little movement.
Flexible joints: This joints allow our body to move.
Bones
Bones are
hard and rigid they are made up of bones tissue. In our body there are 206
bones. They form our skeleton.
TYPES OF BONES:
Flat bones: Protect our internal organs.
Long bones: Are used for movement.
Short bones: Provide support and stability.
The skeleton
This
skeleton`s function is to give shape and support our body and to protect the
internal organs.
Muscles
Muscles are
made up of muscles fibres and the muscles in our body respond to the nervous
system by contracting and relaxing.
TIPES OF MUSCLES
Voluntary muscles: If you want to move them you can move them.
Involuntary muscles: you move them if you want or don`t
want.
The nervous system
Definition:
receives and respond to information from the five sense organs.
The central
nervous system is made up of the brain, spinal cord and the peripheral nervous
system which is made up of the nerves.
Central Nervous System
The brain is the control centre of the central nervous
system and it`s made up of:
Cerebrum: it`s the biggest part of and control the
voluntary movements.
Cerebellum: the cerebellum controls balance, movement and
coordination.
Brain stem: the brain stem controls involuntary movement.
SPINAL CORD: The spinal cord it`s made up of nerve tissue
and run from our brain down our spine.
REPRODUCTION
If a species doesn’t reproduce itself it will become extinct. When an animal reproduces it creates a new
living thing it`s called offspring
Types of Reproduction:
Sexual
reproduction
This method needs a male and a female of the same species.
The ovum is fertilised by a sperm. An egg carried by the female is fertilised
by a sperm from the male.
1.
Oviparous: the embryo grows outside
the female body, inside an egg. The female lay eggs and these eggs are later
hatch into new offspring.
2.
Viviparous: the embryo grows inside
the mother’s body.
3.
Ovoviparous: These animals produce
eggs, but the eggs develop and hatch inside the mother. Later the mother gives
birth to live young.
Asexual reproduction
It`s when
the offspring develop from a part of a parent’s body.
THE
FEMALE REPRODUCTIVE SYSTEM
1
Ovum: the female sex cell. More
than one ovum is called OVA.
2
Ovary: produce the ovum.
3
Uterus: the embryo develops inside.
4
Fallopian tube: Connect the ovaries
to the uterus.
5
Vagina: It is a muscular tube that
connects the uterus to the outside body.
6
Vulva: the external part of the
female reproductive system.
Male
reproductive system
1.
Testes: produce male sex cells
called sperm.
2.
Scrotum: It is a sac where the testes
are located.
3.
Vas deferens: transport the sperm
to the urethra
4.
Prostate gland: produce the semen.
Semen carries sperm and gives its nutrients.
5.
Urethra: Is a tube in the penis.
6.
Penis: deposit the sperm
Puberty
Adolescence
is the stage between childhood and being an adult. Adolescence is a time of
physical, emotional and social change. Puberty takes place during adolescence.
Puberty involves all the physical changes that change our body from a child’s
body into the body of an adult.
We are born with primary sexual characteristics. They
are male or female reproductive system. At puberty secondary reproductive
system develop.
Male: male have lower voices and lots of facial body
hair
Female: have wider hips grow hair in some places.
FERTILIZATION
Fertilization happens when an ovum and a
sperm join to form a new cell called zygote. This cell
contains information called genetic information. The offspring has information
of the father and the mother.
Fertilisation takes
place in the fallopian tube when the ovum is travelling from the ovary to the
uterus. If fertilisation doesn’t happen the uterus expels the ovum trough the
vagina. With small loss of blood called menstruation.
Living things
Living things: All the plant life in an ecosystem is called the flora. All the
animal life in an ecosystem is caleld fauna.
Other living things are fungi, microorganisms and bacteria.
The environment: Physical elements in an environment include air, water, soil,
sunlight, temperature and climate.
Population: When population with each other they form a community.
One
of the most important relationships involves energy. Energy moves through food
chains and food webs elements in the food chain.
1 producers: make their own
food.
2 consumers: they obtain the food by eating other living
things.
2.1
primary: primary consumers eat producers.
2.2
Secondary: primary consumers eat producers.
2.3
Tertiary: tertiary consumers eat secondary
consumers.
3 decomposers: decomposers decompose the remains of other living things.
Humans and ecosystems
Humans perform different activities that
affect the environment.
Deforestation: consist in cutting down long areas of
trees.
Contamination:
A) Air contamination: is the use of fossil,
fuels, petrol, coal …produce CO2. It incises the Earth’s temperature and
causes the global warming.
B) Water contamination It happens when waste
from homes and indices It ben deposit in rivers, lakes …
C) Sand contamination: Soil is polluted by
chemicals from agriculture and waste from industries and homes.
Protection environment
People are trying to protect the enviroment.
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