(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 our hands? What effect is produced in the ball?
(a) If the resultant of all the forces acting on a body is zero, the forces are called balanced forces. These forces do not change the state of rest or of uniform motion of a body but can change the shape of the body. For example, when a balloon is pressed between hands, then balanced forces (equal and opposite forces) act on the balloon due to which the shape of the balloon changes.
If the resultant of all the forces acting on a body is not zero, the forces are called unbalanced forces. These forces change the state of rest or of uniform motion of a body. For e.g., if we push a toy car lying on the ground, it starts moving due to the unbalanced force exerted by our hands.
(b) When we press a rubber ball between our hands, balanced forces acts on it and hence its shape changes.