Inertia

 
 
2.4

 Inertia

 
  Inertia  
  means the tendency of an object to resists changes to its state of rest or uniform motion in a straight line  
     
  Newton's first law of motion  
 
  • states that every object continues in its state of rest or uniform speed in a straight line unless acted upon by an external force.
 
 
  • The larger the mass, the greater the inertia of an object.
 
     
 
Example of inertia

thrown in front when hit something with speed

coin fell down into glass when the paper is push quickly

the items stay at the same place when the tablecloth is pull quickly

the sauce came out after we suddenly stop the moving bottle

the movement of people in the bus when it accelerates or brakes

the movement of the elephant slower if it moves zig-zag

 

Applications of the concept of inertia

  • Knock downwards the handle of a hammer against a hard surface to tightens the loose head of hammer in its wooden handle.

     
  • Shake the branch of apple tree to get the apples fall to the ground.

     
  • Dogs and cats shake their body vigorously to dry their wet fur.
 

Ways of reducing the negative effects of inertia

  • Using seatbelts to prevent the passenger thrown forward due to inertia

     
  • Using airbag to prevent the driver from hitting the sterring wheel

     
  • Fastened the objects on the lorry so that it become part of the carrier

     
  • Strong iron structure between driver's cabin and load ensures the driver safety. (lorry with heavy load)