UNIT 8: LIGHT AND SOUND

UNIT8: LIGHT AND SOUND.

3.-Sound and its characteristics.

3.1.- Sound.

Sound is a form of energy called sound energy. It can produce changes in certain objects.

For example, the sound of an explosion can break windows.

Any vibrating object produces sound. For example our vocal cords vibrate when air passes our throats, creating our voices.

3.2.- Characteristics of sound.

Every object emits a characteristic soun when it vibrates. The different qualities of a sound lets us tell the difference between them:

Intensity: a sound ś intensity can be soft like a whisper or loud like and explosion.

Pitch: A soundś pitch can be high or low. A soundś pitch can be high or low. A soundś pitch will be low if the vibration is produced over a large area. If the area is small, then its pitch is high.

Timbre: it is what lets us differentiate between similar sound, like the difference in timbre of a flute or a saxophone although they are playing the same note.

3.3.- Spreading sound.

The main characteristics are:

• Sound travels in all directions.
• Sound spreads in a straight line.
• Sound is much slower than light. It travels at 340 meters per second.

3.4.- Echo and reverberation

When a sound is emitted and reaches an object, it can reflect or bounce. Depending on the distance of this obstacle, two different phenomena can occur:

• Echo: this happens if the obstacle is more than 17 metres away and there is a clear difference between the reflected and emitted sounds.
• Reverberation: this happens when the obstacle it is as a shorter distance and the reflected soud mixed with the emitted sound.

ACTIVITIES:

1.- Define:

a) sound

b)Intensity

c) pitch

d) timbre

2.- name the main characteristics of spreading sound.

3.- Explain the differences between echo and reverberation.

CANCIONES PARA EL DÍA DE LA PAZ

Aquí os ponemos los vídeos de las tres canciones que vamos a trabajar durante estas semanas con motivo del día de la paz.

PORCENTAJES

ACTIVIDADES PARA EL TEMA 8

PULSA AQUI

VERBOS IRREGULARES Y REGULARES

 

 Practica con los verbos

PULSA AQUI

Práctica de verbos

Pincha aquí

UNIT 7.

INDEX

1.-MAGNETISM

1. Magnets
2. Characteristics of magnets
3. The magnetic poles of the Earth
4. Uses of magnetism

1.1 MAGNETS

Magnets are some materials that can attract certain metals. There are two types of magnets:

• Natural. There are minerals, like magnetite that can attract iron objects.
• Artificial. These are magnets people make from metals, like the ones we puts on the fridge.

All magnets are two parts, their north poles and their south poles.

1.2 CHARACTERISTICS OF MAGNETS

Magnets are two characteristics:

• You can never separate poles of a magnet.
• When we put two magnets together, two things can happen when their poles touch:

• They repel each other if we put the same poles together.
• They attract each other if we put different poles together. 
  
  
  1.3 THE MAGNETIC POLES OF THE EARTH

The Earth´s core is made out of iron and nickel. This makes the Earth act like a large magnet.

Our planet has a north magnetic pole and a south magnetic pole.

A compass always points to the Earth´s magnetic north pole.

1.4.-USES OF MAGNETISM

Magnetism has different uses:

• Orientation. As in the case of a compass.
• Magnets. They are used in many objects, like door locks, bags,…
• Information storage. For example, storing images on videotapes or data on credit cards, mobile phones and computer drive.
• Theft control. Magnetic devices are put on clothing, books to prevent people from stealing them.
• Identification. The magnetic strips on plane and train tickets or health ID cards help identify itineraries or treatments.

ACTIVITIES

1.-Fill in the blank

1. There are two types of magnets __________ and _________ .
2. All magnets have two parts,____________ and ___________.
3. A natural magnet is made up of the mineral ___________________ .
4. Magnets _____________ each other if we put the same poles together.
5. Magnets _____________  each other if we put different poles together.
   

2.-True or false. Check it if it is necessary. 

a)The poles of a magnet can be seperated.

b) If we put the same poles together, they repel each other
c) The earths core is made out of iron and nickel.
d)Earth has a east magnetic pole and a south margnetic pole.
e) A compass always points to the earths magnetic north pole.

3.-What are the 5 different uses of magnetism? Name it.