Question

Two equal and opposite forces with magnitude 2 N act on a stationary body. What is the force on the body ?
a. 4 N
b. 2 N
c. 0 N
d. 1 N

Answer 1

HintWhen two equal and opposite forces act on a stationary body, the body will not move.
This is because the net force on the body is zero, so the body will remain stationary.

Complete step-by-step solution:
A force is the push or pull on an object. Force is a vector quantity which is defined by its magnitude and direction. Forces are described not only by how strong they are, but also by the direction in which they act.
The overall force on an object, called the net force which is found by combining all of the forces acting on the object. The size of the net force determines whether the object’s motion changes. The direction of the net force determines the direction of the object’s motion.

The forces combining by following ways :
When two forces act in the same direction, they add together.
When forces act in opposite directions, they are combined by subtracting the smaller force from the larger force.
When you add equal forces in the opposite direction, the net force is zero.

Two equal and opposite forces $F_1$ and $F_2$ act on a stationary body then
\[{F_{1\;}} = {F_2} = 2N\]
The net force act on a body is
\[F = {F_{1\;}} - {F_2} = 0\]
So the net force on the body is zero when equal and opposite forces act on a body.
The answer is option (C).

Equal forces acting in opposite directions are called balanced forces. Balanced forces acting on the body will not change the object’s motion.

Note:-
The direction of the resulting force (resultant) is the direction of the larger original force. When there is a net force acting on an object, the forces are said to be unbalanced. When an equal and opposite force is applied to a body. Both the opposite forces balance each other and hence the body doesn't move.

Additional information :
Unbalanced forces cause an object to start moving, stop moving, or change direction. Unbalanced forces acting on an object will change the object’s motion. Unbalanced forces can also stop a moving object. The three main forces that stop moving objects are friction, gravity and wind resistance. The direction of the resulting force (resultant) is the direction of the larger original force. When there is a net force acting on an object, the forces are said to be unbalanced.