Online Physics lessons from the Massachussets Institute of Technology

Professor Lewin delivers his lectures with the panache of Julia Child bringing French cooking to amateurs and the zany theatricality of YouTube’s greatest hits. He is part of a new generation of academic stars who hold forth in cyberspace on their college Web sites and even, without charge, on iTunes U, which went up in May on Apple’s iTunes Store.

In his lectures at ocw.mit.edu, Professor Lewin beats a student with cat fur to demonstrate electrostatics. Wearing shorts, sandals with socks and a pith helmet — nerd safari garb — he fires a cannon loaded with a golf ball at a stuffed monkey wearing a bulletproof vest to demonstrate the trajectories of objects in free fall.

He rides a fire-extinguisher-propelled tricycle across his classroom to show how a rocket lifts off.
Last week, Yale put some of its most popular undergraduate courses and professors online free. The list includes Controversies in Astrophysics with Charles Bailyn, Modern Poetry with Langdon Hammer and Introduction to the Old Testament with Christine Hayes.

M.I.T. recently expanded its online classes by opening a site aimed at high school students and teachers. Judging from his fan e-mail, Professor Lewin, who is among those featured on the new site, appeals to students of all ages.
“We have here the mother of all pendulums!” he declares, hoisting his 6-foot-2, 170-pound self on a 30-pound steel ball attached to a pendulum hanging from the ceiling. He swings across the stage, holding himself nearly horizontal as his hair blows in the breeze he created.

The point: that a period of a pendulum is independent of the mass — the steel ball, plus one professor — hanging from it.

“Physics works!” Professor Lewin shouts, as the classroom explodes in cheers.

“Hi, Prof. Lewin!!” a fan who identified himself as a 17-year-old from China wrote. “I love your inspiring lectures and I love MIT!!!”
The professor, who is from the Netherlands, said that teaching a required course in introductory physics to M.I.T. students made him realize “that what really counts is to make them love physics, to make them love science.”

He said he spent 25 hours preparing each new lecture, choreographing every detail and stripping out every extra sentence.

“Clarity is the word,” he said.

The root of the plants

QUIZ

1. Which is the part of the plant that absorbs substances from the ground?
a) The leaves.
b) The flowers.
c) The roots.
d) The stem.

2. Which the these is a type of root?
a) Graft.
b) Straight.
c) Short.
d) Green.

3. What do the hairs of the lower layer of the root absorb?
a) Water.
b) Nothing.
c) Mineral salts.
d) Water and mineral salts.

4. Different types of roots depend on...
a) Their form and colour.
b) Their colour and function.
c) Their form and function.
d) Their form.

5. Where are the secondary roots born?
a) From the flowers.
b) From the main roots.
c) From the leaves.
d) From the stem.

A Quiz by Tania

The root of plants

Some illens relationed with food.

The most frecuent illens relationed with nourishment are: malnutrition, obesity, anorexia and bulimia.

-Malnutrition: It's caused by a lack of nowishing meal due to a bad diet. This illens is the most important reasons of dead in the chidren in the process of developement countries.

-Obesity: It's about too much grease corporal, so; weigh is raised. This one is caused by an excessive consumption of energetic alimony specially greasy food and sweets. Moreover people don't practise gymnastics.

-Anorexia: People who suffer anorexia is afraid of putting on weight because they aren't able to see. How their body is really, so ; sick people see themselves very fat. Finally they give eating and this causes an extreme slimnes . People can die.

-Bulimia: It's produced beacause of an extreme worrying about weight. The ill person eats too much food and in adition he/she hides in orden not to be seen.

Grammar Tip: The and uncountable nouns

Remember: Do not use THE when talking in general about uncountable names of substances/materials like oil, silver, aluminium, coke, pasta or cadmium

The magnesium and the potassium

The magnesium is the chemical element of symbol Mg and atomic number 12. The atomic mass is of 24.31. It is the seven element in abundance constituting of the order of 2 % of the terrestrial bark and three more abundant dissolve in the water of sea. The ion magnesium is essential for all the alive cells. The pure metal is not find in the nature. Once produced from of the salts of magnesium, this alkaline-terrestrial metal is use as a element of alloy.


The potassium is a chemical element of the periodic table which symbol is K (of the Latin Kalium) and which atomic number is 19. It is an alkaline metal, white-silver what abound in the nature, in the elements related to the salt water and other minerals. It oxidi rapid in the air, is very a reagent, specially in water, and looks chemical the sodium. It is a chemical element essential.

THE OIL

Once extracted the oil is transported across pipelines and immediately petroleum ships up to the refineries. These are industrial plants where efectua the transformation of the crude oil in finished products.

In the refineries, the oil separates by means of distillation divided in groups of compounds that have a similar size.

The by installments distillation consists of the separation of two components different from the oil as susdiferentes points of evaporation. For it a tower of division is in use.

· The crude oil enters the base and is to top temperatures to 400ºC and begins to boil.

· The components more heavy stay in the low part of the tower.

· Less heavy others rise only up to certain height and there they become condensed and are extracted.

·Despues, every fraction can be submitted to new processes to obtain his last components

·The componientes mas liegeros rise up to the top zone of the tower where they are extracted.

METALS

1) COOPER:

- Colour: red.

- Characteristics:
- Malleable.
- Good electricity conductor.

- Uses:
- Wires that carry electricity.
- Pipes.
- Decoration.

2) SILVER:

- Colour: white.

- Characteristics: It’s the best electricity conductor.

- Uses:
- Jewellery.
- Electrodes for electrolysis.

3) GOLD:

- Colour: yelow.

- Characteristics:
- Heavy.
- Malleable.

- Uses:
- Jewellery.
- Ornaments.

4) PLATINUM:

- Colour: silver white.

- Characteristics:
- Very heavy.
- Hard/ tough.

- Uses:
- Jewellery.
- Electrodes.


5) MERCURY:

- Colour: silver white.

- Characteristics:
- A lot of metals are dissolved in it.
- Toxic.

- Uses: It was used to make thermometers, barometers, etc.

6) ZINC:

- Colour: bluish-white.

- Characteristics: easily broken/fragile.

- Uses:

- To make galvanized iron.
- Cans, jerry cans...
- An alloy of cooper and zinc in brass.

7) TIN:

- Colour: white.

- Characteristics: soft and malleable.

- Uses:
- Soldering.
- To make tinplates.
- Alloys (bronze).


8) LEAD:

- Colour: grey.

- Charasteristics: It melts easily.

- Uses:
- Welding.
- To make bullets, cannon balls, pellets,...


9) ALUMINIUM:

- Colour: silver white.

- Charasteristics: light and malleable.

- Uses:
- To make planes and other vehicles.
- Utensils.


10) URANIUM:

- Colour: dark dun or black with yellow or green spots.

- Characteristics:
- Heavy.
- Radioactive.

- Uses: nuclear energy.

11) IRON:

- Colour: grey (mild iron).

- Characteristics: When it’s outdoors it goes rusty quickly.

- Uses:
- Building materials.
- Boilermaking, etc.

Oxygen

OXYGEN

There is planty of it in the lithosphere and the hydrosphere, more than any other element. It can be mixed with air and it can be combined with water and with many other minerals.

· PROPERTIES: It’s a colourless, odeorless and tasteless gas and lightly water soluble. Oxygen has a great chemical activity, that’s why it can react with hearly all elements forming a lot of combinations that are in general called oxides.
It is essential for the breathing process in living things.
You can find it in two ways: normal oxygen, this one has its molecules formed with two atoms of oxygen and ozone, its molecules have three oxygen atoms.

· HOW TO OBTAIN IT: It can be obtained in laboratories in a very easy way, heating chlorine potassium.
For industry applications, big quantities of oxyegn can be obtained from air and from water.

· APPLICATIONS: Planty of oxyegn is used in autogenous welding. It’s also used in medicina, for diving, for climbing,…

THE ROOT OF THE PLANTS


The root of the plants is the part of the plant that pays attention to the ground to which it is nourished. But at the present time the botanists affirm that a difference between root and stem does not exist. We could speak of the root as of the part of the plant that absorbs substances of the ground.

The end of the root is covered by the layer or caliptra, followed of another cap with absorbent hairs that allow to the acquisition of water and mineral salts. When the plant ages, these hairs fall. The secondary roots are born of the main root.

Different types from roots, depending of their form and function exist: when they work like reserve organs, the main root sinks in the ground. Also roots with ramifications that extend in beams and aerial roots in plants exist that are not fixed in the ground... In addition we can hear other terms referred to the types by roots: fibrous, graft, napiforme, to columnar...

CALCULATION OF THE DEFORMACIÓN FORCE ONE THAT PRODUCED IN WHARF

You need this:

• Wharf


• Bracket


• A walnut


• A metal bar


• Portweights


• Weights


• Paper
  
• Tape

How to make the experience:

1. Build a rule of paper and set this rule to the metal bar of the apparatus. Thus it is vertical.


2. Hang wharf bar and then suspended portapesas at the end of the dock. Notes on the scale length and write their values.


3. Hang the wharf with different weights (25, 50, 75, 100 and 125 g) and enter what is its length reaches the wharf with each of the weights.

You can make this experience anywhere with these elements and these steps. It is a curious experience and funny.

The oil

Oil is a fossil fuel. Its colour is brown.It was formed many years ago. Organic matter made of the remains of little animals formed a deposit in the bottom and was covered by a thick layer of sediment.

The conditions to favour the formation of oil are:

-Not very much deep sea, with many nutrients.

-Sediments.

-Not much movement of water in the bottom.

The products formed by oil to appear in the three states of matter:

-Liquid: raw

-Solid: tarmac

-Gaseous: natural gas

Some adrift of oil are:

-Tarmac

-Gas

-Petrol

Bulimia and anorexia

Bulimia is a mental disorder related to food.The person who has it eats a lot of food in a short time. Then, she thinks she is fat and feels guilty. The person induces vomit and expels the food that she has ingested.
Anorexia is a similar illness, but it consists in not eating anything.These people think that their weight is very high.
These two illnesses can end up in death but many times they have cure becouse now, there are specialized clinics.

Dissolutions

Hi!

I'm going to write about dissolutions.

Dissolutions are mixtures which are formed by dissolute and solvent. Amount of dissolute has to be smaller then amout of solvent. There are two kinds of dissolutions : homogeneous dissolutions and heterogeneous dissolutions.

In homogeneous dissolutions we can't recognize their component.

We can preparate dissolutions at the laboratory when we study chemistry.

Bye!

[ Instruments to measure the temperature ]

The thermometers are a instruments that measure the temperature.

There are three types of thermometres:

●Alcohol thermometre of laboratory.

●Clinical thermometers of mercury.

●Thermometer of alcohol of environment.

To measure the temperature,there are two scales:

● The centigrade temperature scale or celsius: in this scale,the unit is a centigrade degree (ºC).

● The scientific use the Kelvin scale.In this scale,the unit is the Kelvin (K).One kelvin has got the same size that a centigrade degree,but the cero of Kelvin scale is -273ºC and yourname is absolute cero.

To transform one value of a scale to other is easy:Kelvin temperature = centigrade temperature+273

THE SIMPLE DISTILLATION

Is in use for separating a dissolution formed by two liquids depending on her different boiling-points.

When one makes boil the dissolution contained in the flask, the volatile solvent that has a minor boiling-point, it evaporates and leaves in the flask a residue of soluto not volatile.

To gather the solvent like that evaporated, one makes him happen for a condenser in the one that circulates cold water. There there becomes condensed the steam, which falls down in a glass.

Physics and Chemistry

Physics is the science of matter and its motion, as well as space and time the science that deals with concepts such as force, energy, mass and charge. As an experimental science, its goal is to understand the natural world.

Chemistry is the science concerned with the composition, structure and properties of matter, as well as the changes it undergoes during chemical reactions. Chemistry is a physical science related to studies of various atoms, molecules and crystals.

filtration

Filtration is the process of removing suspended solids from water by passing the water
through a permeable fabric or porous bed of materials. Groundwater is naturally filtered
as it flows through porous layers of soil. However, surface water and groundwater under
the influence of surface water is subject to contamination from many sources. Some
contaminants pose a threat to human health, and filtration is one of the oldest and
simplest methods of removing them. Federal and state laws require many water systems
to filter their water. Filtration methods include slow and rapid sand filtration, diatomaceous
earth filtration, direct filtration, packaged filtration, membrane filtration, and
cartridge filtration.

Helium

Helium is one of the so-called noble gases. Helium gas is unreactive, colourless, and odourless. Helium is available in pressurised tanks.
Elemental helium is a colourless odourless monoatomic gas. Helium is the second most abundant element in the universe after hydrogen. α particles are doubly ionised helium atoms, He2+.
Helium is used in lighter than air balloons and while heavier than hydrogen, is far safer since helium does not burn. Speaking after breathing an atmosphere rich in helium results in a squeaky voice (don't try it!).

THE OIL

The oil is a fossil fuel of black color and oily aspect that impregnates certain rocks.Create it does million years from organic matter contained in the remains of small animals, algae and other beings who died in the sea, they settled in the fund and, little by little, they were covering of a dense cap of materials. For lack of osigeno did that they were increasing, multiplying in number, the anaerobic bacteria that make ferment the organic matter.

The conditions that favor the creation of the oil are:
- Slightly deep and rich seas in nutrients.
- Fluvial contributions.
- Little water movement in the fund.

The majority of the oil is in the stock exchanges impregnating rocks. These finds are to thousands of meters of depth, because of it to extract the oil it is necessary to make a well and take it up to the surface.

Types of food

• Food energy: they are a source of energy for our bodies to function and do their vital functions. These are foods with glícidos and lipids. These foods are bread, chocolate, grease ...



• Food plastics or trainers: They are required to form cells, tissues and organs. They are essential for nutrition and have many proteins. These foods are fish, meat, yogurth ...

• Food regulators and protectors: they are essential to our body can use correctly other foods have many vitamins, minerals and water. These foods are fruits and vegetables.

Practise with Robbie Williams