Activitiy 1. daily life involving work. List them. Discuss with your friends whether work is being done in each situation. Try to reason out your response. If work is done, which is the force acting
Answers
Answer:
Objective
This topic gives an overview of;
Force - A Push or a Pull
Forces due to an Interaction
Exploring Forces
Change in State of Motion
Change in Shape of an Object
Contact Forces
Non-contact Forces
Force
You have learnt how objects move. You also know that a moving object like a ball rolling on the ground slows down. Sometimes it may change its direction of motion. It is also possible that the ball may slow down and also change its direction. what makes an object to slow down or go faster, or change its direction of motion?
Let us recall some of our everyday experiences. What do you do to make a football move? What do you do to make a moving ball move faster? How does a goalkeeper stop a ball? How do fielders stop a ball hit by a batsman? A hockey player changes the direction of the moving ball with a flick of the stick. In all these situations the ball is either made to move faster or slower or its direction of motion is changed.
We often say that a force has been applied on a ball when it is kicked, pushed, thrown or flicked. What is a force? What can it do to bodies on which it is applied?
Force - A Push or a Pull
Actions like picking, opening, shutting, kicking, hitting, lifting, flicking, pushing, pulling are often used to describe certain tasks. Each of these actions usually results in some kind of change in the motion of an object. These terms be replaced with one or more terms. Let us find out.

The Below table gives some examples of familiar situations involving motion of objects. You can add more such situations or replace those given here. Try to identify action involved in each case as a push and/or a pull and record your observations.
S.NoDescription of the situation1Moving a book placed on a table2Opening or shutting a door3Drawing a bucket of water from a well4A football player taking a penalty kick5A cricket ball hit by a batsman6Moving a loaded cart8Opening a drawer
Do you notice that each of the actions can be grouped as a pull or a push or both? Can we infer from this, that to move an object, it has to be pushed or pulled?
In science, a push or a pull on an object is called a force. Thus, we can say that the motion imparted to objects was due to the action of a force. The international unit used to measure force is newton. A force can change the shape and size of an object.
Forces due to an Interaction
Suppose a man is standing behind a stationary car. Will the car move due to his presence? Suppose the man now begins to push the car, that is, he applies a force on it. The car may begin to move in the direction of the applied force. Note that the man has to push the car to make it move.
The below pictures shows three situations that may be familiar to you. In the Figure (a), both the girls appear to push each other while the pair of girls in Figure (b) are trying to pull each other. Similarly, the cow and the man in Figure(c) appear to