Friction

Question 1 Name the force which always opposes motion?

Question 2 What is the direction of force of friction acting on moving object?

Question 3 Define the term friction?

Question 4 When we try to push a heavy box kept on ground it does not move at all. Which force is preventing this box to move forward. Where does this force acts?

Question 5 A ball moving on the ground slows down gradually and stops after covering some distance. Which force is acting on ball?

Friction

(1) When we push a box lying on the floor with a small amount of force, it does not move at all. It means that the surface of floor, on which the box is resting exerts some force on the box which acts in a direction opposite to force of our push. This natural force between the floor and the bottom of the box which opposes the motion of box on the floor is friction.

(2) A ball moving on the ground slows down gradually and stops after covering some distance. A force is exerted by the ground on the moving ball which opposes its motion and brings it to stop. A force is exerted by the ground on the moving ball which opposes the motion and bring it to stop. This force which opposes the motion of ball on the ground is also fiction.

The force which always opposes the motion of one object over another object in contact with it is called friction.

 

Friction occurs between the two surfaces which are in contact with each other. When we push a heavy box kept on floor, the force of friction occurs between the surface of floor and bottom of the box.

In the case of a ball rolling on ground, friction occurs between the surface of ground and the surface of ball.

Friction is a force which occurs when the two objects tend to slide over each other and even when they are actually sliding over each other.

Direction of Force of Friction

The force of friction always opposes the motion of one object over another object. So the force of friction acts in a direction opposite to the direction in which an object moves.

Activity

Place a book on the table. Give a push to this book towards the right side. We will find that the book moves through some distance to the right side and then stops. Since the book moving towards right side stops on its own, this means that the force of friction is acting on it in the opposite direction which is opposing its motion and making it stop. When the force is applied by our push to move the book towards right side then the force of friction acts towards left side. Now give up Push to the book towards the left side we will find that the book moves some distance towards the left side and then stops. Since the book moving towards left side stops on its own this means that the force of friction is acting on it in the opposite direction which is opposing its motion and making it stop. When the force is applied by our push to move the book towards left side, then the force of friction acts towards the rights side.