Pulley

How do pulleys make work easier?

• they change the direction of a force

• they change the amount of force required

• the distance over which the force is applied

• the measurement of an object

What is a pulley?

• a simple lifting machine consisting of a rope which unwinds from a wheel on to a cylindrical drum or shaft joined to the wheel to provide mechanical advantage.

• a rigid bar resting on a pivot, used to help move a heavy or firmly fixed load with one end when pressure is applied to the other.

• a wheel with a grooved rim around which a cord passes. It acts to change the direction of a force applied to the cord and is chiefly used (typically in combination) to raise heavy weights.

• a piece of wood, metal, or some other material having one thick end and tapering to a thin edge, that is driven between two objects or parts of an object to secure or separate them.

How do fixed pulleys make work easier?

• they change the direction of a force

• they change the amount of force required

• the distance over which the force is applied

• the measurement of an object

Identify the type of pulley

• fixed

• moveable

• block and tackle or pulley system

Identify the type of pulley

• Fixed

• Moveable

• Block and Tackle or pulley system

The diagram shows a movable pulley system. When moving a load, this pulley system changes the —

• direction of the force.
• amount of force needed.
• pull of gravity on the load.
• overall mass of the rope.

What is the difference between a fixed pulley and a movable pulley

• 
  The single fixed pulley changes the direction of the force applied, while the single movable pulley provides a mechanical advantage by reducing the amount of force needed to lift an object.

• 
  The single fixed pulley and the single movable pulley both change the direction of the force applied.

• 
  The single fixed pulley reduces the amount of force needed to lift an object, while the single movable pulley changes the direction of the force applied.

• The single fixed pulley provides a mechanical advantage by reducing the amount of force needed to lift an object, while the single movable pulley does not provide any advantage.

Look at this Simple Moveable Pulley. What mechanical advantage does it give us?

• a lot

• 1

• 2

• 10

What is the mechanical advantage of this pulley?

(a)  

What is the mechanical advantage of this pulley system?

(a)