Question

(a) What do you understand by the terms "balanced forces" and "unbalanced forces"? Explain with examples.
(b) What type of forces − balanced or unbalanced − act on a rubber ball when we press it between out hands? What effect is produced in the ball?

Answer 1

(a) Balanced forces: If the resultant of all the forces acting on a body is zero, the forces are called balanced forces.
Example: When we push a concrete wall with our hands the wall doesn't move. This is because the force by us is balanced by the other forces acting on the wall.

Unbalanced force: If the resultant of all the forces acting on a body is not zero, the forces are called unbalanced force.
Example: If we push a toy car lying on the ground, we find that the toy car starts moving. This is because the force exerted by our hand is not balanced by the other forces acting on the toy car.

(b) The balanced forces change the shape of the rubber ball when we squeeze it.

When we press a rubber ball between our two hands, the shape of the ball alters from spherical to oblong. This is because two equal and opposite forces (balanced force) are applied by our hands.