Frictional force

6.2  Frictional force
 
The direction of the frictional force is always opposite to the direction of the movement of the object. Frictional force can slow down or stop a moving object.
 
Definition
     
  Frictional force is the force when two surfaces are in contact  
 
 
Factors That Affect Frictional Force
     
 
Types of Surface Mass of the Object
  • Smooth surfaces produce less frictional force
    (The smoother the contacted surfaces, the lesser the frictional force produced)
  • Light objects produce less frictional force
    (The lighter the mass of the object, the lesser the frictional force produced)
  • Rough surfaces produce great frictional force
    (The rougher the contacted surfaces, the greater the frictional force produced)
  • Heavy objects produce great frictional force
    (The greater the mass of the object, the greater the frictional force produced)
 
     
 
Frictional Force
     
 
Increasing the frictional force Decreasing the frictional force
  • Using rubber mat
  • Using rough surface and stripes pattern 
  • Using magnesium carbonate lime powder
  • Using lubricant oil
  • Using rollers, balls bearings or wheels
  • Using wax
  • Using grease
  • Using boric acid flour

 

 
 
Advantages and Disadvantages of Frictional Force
     
 
Advantages Disadvantages
  • Enables an object to be held without slipping
  • Enables humans to walk or run without slipping
  • Enables an object to remain stationary
  • Enables humans to climb a tree
  • Produces loud sounds
  • Generates heat and causes the surface to become hot
  • Frictional force wears out a scraped surface
  • Causes heavy objects to be difficult to pull or push