Page 1 - LN
P. 1

LESSON NOTES
               Force
               A push or pull on a body is called force.


               Characteristics of force:
              Force has both magnitude and direction, making it a vector quantity.
              It is measured in the SI unit of Newton
              It is represented by the symbol F.
               Effects of Force:
              It can move a stationary object.
              It can stop a moving object
              It can change the speed of a body.
              It can change the direction of Motion of a body.
              It can change the shape of a body.
               Balanced and Unbalanced Forces
               (i) Balanced Forces:  If the resultant of applied forces is equal to zero, it is called
               balanced forces.
               Foe example: In the tug of war game when the force applied by both teams is equal in
               magnitude then the rope does not move in either side. This is due to the balanced
               forces in which resultant of applied forces comes out to be zero.





















               Characteristics:


              Balanced forces do not cause any change of state of an object.
              Balanced forces are equal in magnitude and opposite in direction.
              Balanced forces can change the shape and size of an object. For example: When we
               press a balloon from opposite sides, the size and shape of balloon is changed.
               (i) Unbalanced Forces:  If the resultant of applied forces are greater than zero, the
               forces are called unbalanced forces.
               To move an object unbalanced forces are to be applied from the opposite directions. In
               case of unbalanced forces acting on a body, it moves a in the direction of the greater
               force.

               Unbalanced forces can:
   1   2