1. Unit 3
MECHANISM

2. 1. Simple Machines
Simple machines are devices human use to complete tasks using less force.
Inclined planes.
Inclined planes are used to move up a heavy object to a higher position by a surface that connects the low and high levels.
A small angle means less force to apply to the object and large angle means more force to apply to.

3. 1. Simple Machines 2. Wheel and axle assemblies ( Montaje rueda y eje)
In a wheel and axle assembly, the axle is located at the centre of the wheel joined to it to form an integral part of the assembly.
If the wheel moves then the axle will move as well in the same direction.

4. 1. Simple Machines 3. Screws
Screws are the simplest elements used to convert a rotational motion into a forwards or backwards linear motion or movement.
They consits of metal cylinder with helicoidal thread. When the distance beetween each thread is short you will need more time to turn the screw.

5. 1. Simple Machines 4. Levers
Levers are rigid bars which transmit effort and movement. They rest on a support point called a fulcrum.

6. 1. Simple Machines

7. 1. Simple Machines

8. 1. Simple Machines

9. 1. Simple Machines-Exercises

10. 1. Simple Machines-Exercises

11. 1. Simple Machines-Exercises

12. 1. Simple Machines-Exercises

13. 1. Simple Machines-Exercises
Look at the picture below. What is the force necessary to lift the wheelbarrow?
What type of lever does the picture correspond to? Draw the force diagram to help you to resolve the problem.

14. 1. Simple Machines-Exercises
Look at the picture below. The fish which pulls the fishing rod is applying a force of 30 Newtons (N). What is the force necessary to take the fish out of water?
What type of lever does the picture correspond to? Draw the force diagram to help you to resolve the problem.

15. 1. Simple Machines-Exercises
Look at the picture below. The stone has a resistance of N. The force arm has a length of 2 m and the resistance arm has a length of 0,50 m . What is the force necessary to apply to lift the stone?
What type of lever does the picture correspond to? Draw the force diagram to help you to resolve the problem.

16. 1. Simple Machines-Glossary
Inclined plane: Plano inclinado
Slope: Inclinación
Axle assembly: Montaje de un eje
Screw / bolt: Tornillo
Nut: Tuerca
Lever: Palanca
Fulcrum: Punto de apoyo
Force arm: Brazo de fuerza
Resistance arm: Brazo de resistencia
Seesaw: Balancín
Wheelbarrow: Carretilla
Fishing rod: Caña de pescar