Force – Definition and Example

Force

 Key Concepts

• Force- definition
• Force-a push or a pull

Introduction

We do a lot of activities in our daily lives that involve application of force in one way or the other such as moving from place to place, playing outdoors, doing school activities, etc. In this section we will be learning about this force in detail. 

Explanation

Force: 

The pictures below show some of the activities that one performs on a day to day basis. 

The people shown in the pictures above are indeed applying force on an object, such as in the first picture, a person is applying a force on the trolley, in the third picture the body is applying a force on a football and in the fifth picture the woman is applying a force on the bag. As a result, these objects start moving. In other words, their state of motion is changed on application of force. 

Actions such as opening, closing, punching, flicking, hitting, lifting, picking, pressing, pulling, bouncing and pushing, are used to describe certain tasks and result in the application of a force on an object. Each of the above actions leads to changing the state of the motion of a body. 

Force- A Push or a Pull: 

The table below shows some commonly performed actions and their grouping into push or pull, or both. 

It can be concluded from the table that, each of the actions can be grouped into a push or a pull, or both push and pull. Thus, objects can be moved only when they are either pushed or pulled in some way. 

It is also known that, when a force is applied on an object, it moves. Thus, it can be concluded,  

“A force is a push or a pull on an object.” 

Questions and Answers: 

1. A child is writing on a notebook using a pen. In which action category can you group his action? Explain. Who applies force on whom? 

Answer: 

• The child pushes the nib of the pen on the paper while writing. 
• He also drags (pulls) the pen towards the right to keep on writing. 
• Hence, his action of writing on a paper can be grouped both under push and pull. 

• Here, the child applies a force on the pen by pushing and pulling it on the paper. 

2. Two children are playing see saw in a park. In which action category can you group their action? Explain. Who applies force on whom? 

Answer:  

• The child 1 who is closer to the ground pushes the ground to raise up, making her friend (child 2) go down towards the ground. 
• Now child 2 again pushes the ground to raise up, making child 1 go down towards the ground. 
• Thus, this action can be grouped under push category, as no pulling is involved. 
• Here both the children apply a force on the ground by pushing on it whenever they get close to it. 

Summary

1. Actions such as opening, closing, punching, flicking, hitting, lifting, picking, pressing,
   pulling, bouncing and pushing are used to describe certain tasks and result in the
   application of a force on an object.
2. Each of the above actions leads to a change in the state of motion of a body.
3. Each of the actions can be grouped into a push or a pull or both push and pull.
4. A force is a push or a pull on an object.