Question

3.
comes to play to counter balance the applied force on the body
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Answer 1

Explanation:

The maximum frictional force present when a body just tends to slide over the surface of another body is known as the static friction. Dynamic Friction: The frictional force which is effective when two surfaces in contact with each other are in relative motion with respect to each other is known as dynamic friction.

Answer 2

When we counter the applied force act on the body, then either the body or the object will move against the applied force.

• When there is a balanced force act on an object at rest, the object will not move.  

• If we push against a wall, the wall pushes back with an equal but reverse force.  

• Neither we nor the wall will move. Forces that lead to a change in the motion of an object are unbalanced forces.

Hope it helped...