Friction

Q1. What is force?

A force is a push or pull that changes the state of the object on which it acts. A force can be caused by direct or indirect interaction between the objects.

Q2. List different effects of force. Give a suitable example in each case.

1. Force can make a stationary object move.

eg. Pushing pedals of bicycle to make the wheels turn.

2.Force can increase or decrease the speed of a moving object.

eg. When force is applied on pedals of a cycle, it moves fast and when force is reduced, speed of the cycle slows down.

3.Force can change direction of a moving object.

eg. A hockey player changes the direction of the moving ball with a flick of the stick.

4.Force can change the shape of an object.

eg. Clay modeling

Q3. What are balanced forces?

Forces that are equal in magnitude but opposite in direction are called balanced forces.

eg. When an object is not moving by applying a force in opposite direction.

Q4. What are unbalanced forces?

Forces that act on a body and causes a change in it are called unbalanced forces.

eg. If you can lift a heavy box, then the force exerted on it is unbalanced.

Q5. Define resultant force (net force).

The resultant force is described as the total amount of force acting on the object or body along with the direction of the body.

eg. If two boys push a rock in the same direction, then -

Net force – F1+F2

If two forces act in the opposite direction on any object, then

Net force- F1-F2(Greater force-smaller force)

NOTE - When the net force is zero, the object does not move. Thus, the applied forces are balanced.