We studied Force previously as a push and pull on the body

 

push pull image.jpg

 

But that is an incorrect definition.

To correct it, first lets study what force can do

 

Different Effects of Force

 

Force can

  • Move stationary object
  • Stop moving object
  • Change speed of the object
  • Change direction of a moving body
  • Change shape of a body

 

Force can move stationary object

A footballer kicking a ball

kicking a football.gif

Force can stop moving object (Make Moving Object Stationary)

A fielder catches the ball

Cricker catching the ball.gif

 

 

Force can change speed of moving body

A footballer passes ball to another footballer

WorldCup.gif

 

 

Force can change direction of moving body

A batsman hitting a ball

PowerlessNearCaudata-size_restricted.gif

Force can change shape of an object

We can change shape of object by exerting force (putting force)

Making roti.gif

 

So, we see that the push and pull definition of force is wrong. Let's look at a new definition

Definition of Force

We can also define force as something which can

Move a stationary object or

Make moving object stationary or

Change speed,direction, shape or size of moving body

 

Questions

Q 2 Page 118 -  In the following example, try to identify the number of times the velocity of the ball changes:
“A football player kicks a football to another player of his team who kicks the football towards the goal. The goalkeeper of the opposite team collects the football and kicks it towards a player of his own team”.
Also identify the agent supplying the force in each case.

View Answer

  1. Class 9
  2. Chapter 9 Class 9 - Force and Laws Of Motion

About the Author

CA Maninder Singh's photo - Expert in Practical Accounts, Taxation and Efiling
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 9 years and a teacher from the past 16 years. He teaches Spoken English, Written English, Grammar and Vocabulary at Englishtan.