George de Mestral observed that cockleburs were sticking to his socks after a hike. This gave him the idea to create a fastening that could easily attach and detach two pieces of fabric, like Velcro. He invented Velcro based on this observation of how the burrs attached to his socks.

1. Las Máquinas, los aparatos y los inventos

2. Yo soy George de Mestral In 1948, the Swiss mountaineer, George de Mestral, observed during an excursion that his socks had small cocklebur stuck to them. Upon seeing them hooked to his sock fabric, he realized the same idea could be applied to unite and separate two pieces of tape. From this, he invented Velcro.

3. Yo soy... En 1948, el montañero suizo ____________________ observó cómo durante una excursión, sus _______ se habían llenado de pequeñas ________ llamadas arrancamoños. Al ver de qué manera los pequeños ________ de las semillas se habían enganchado al tejido de los calcetines, se le ocurrió ________ ese mismo ___________ para poder unir y separar fácilmente dos ________. Asi inventó el _______.

4. 1. Las máquinas We are very accustomed to using machines and appliances; therefore, we rarely discuss how to use them. There are many types of machines that make our lives easier: buses, washers, phones, microwaves, the list is never ending.

5. 1. Machines (simple and complex) ¿C ú al son máquinas sencillas? Y ¿máquinas complejas?. Dibujad dos máquinas m á s

6. 2. Simple Machines Some machines appear very simple because they have a simple mechanism. People or other animals provide the force for these machines to achieve their function. Examples of simple machines include a cart, scissors, and a swing.

7. 2. Simple Machines Dibujad dos ejemplos más:

8. 3. Complex Machines A car with gasoline can circle around the streets and highways. It can transport people and carry heavy objects. Cars are able to achieve their function while minimal effort is exerted by the driver. We can say the same about a crane, a washer or a train. These types of machines are called complex machines .

9. 3. Complex Machines Marcad las maquinas que no son complejas. Explicad.

10. 4. The tools When we want to tighten a nut we use a wrench. To nail a nail we use a hammer. To tighten a screw we need a screwdriver. Tools, such as the wrench , the hammer and the screwdriver are examples of simple machines. With the help of the simple machines, we are able to accomplish a job while using our energy in an efficient way.

11. 4. The tools Dibujad y escribid (en íngles y español) cada una de las herramientas: hammer, wrench, screwdriver, nail and screw:

12. 5. Pulleys To lift a bucket of water from a well, we cannot throw the rope; we put the cord into a wheel at the top of the well and then lower it. Then we can lift the bucket with less effort.

13. 5. Pulleys Dibujad un ejemplo para los dos párafos de abajo. Explicad. If we want to move a heavy object we can use a bar or rod to help with the object On occasions, the top of a can is very tight and we have to use a tool to open it.

14. 6. Classifications of balances First type of balance – the pivot point is between the force and the resistance like in a balance beam or in scissors. Second type of balance- The resistance is between the pivot point and the force, such as in a wheelbarrow. Third type of balance- The force is between the resistance and the pivot point, such as in tongs. A balance beam, wheelbarrow, scissors, tongs and a bottle opener are examples of different types of balances .

15. 6. Completa el recuadro Tipo de palanca El dibujo La maquina Second class lever (palanca de tercer género) Wheelbarrow Second class lever (palanca de tercer género) Can opener Third class lever (palanca de tercer género) Tongs First class lever (palanca de primero género) Scissors

16. 7. Modern inventions Vehicles, like cars, planes, boats and buses allow us to transport people and merchandise quickly. Many of these function due to other inventions, such as the internal combustion engine . Electric appliances , such as heaters, stoves, irons, refrigerators and drills are machines that use electricity. Electrical appliances which are used in the home are called domestic appliances. (Dibujad un ejemplo)

17. 7. Modern inventions Telecommunication , such as phones, televisions, radios and computers allows us to communicate between great distances. (Dibujad un ejemplo). Instruments of measurement and observation , such as the compass, radar, telescopes and microscopes allow us to study nature and obtain exact measurements. (Dibujad un ejemplo).

18. 8. Wheel The wheel is one of the most important inventions by humans. It revolutionized transportation and paved the way for many other inventions.

19. 8. Inventos modernos-Modern inventions Dibujad diez ejemplos de inventos modernos que tengan por lo menos una rueda .

20. FIN