from Faisalabad,Pakistan
The forces acting on a stationary object are:PushPullGravity
It remains stationary
In that case, the object's velocity won't change.
No. An object that has no net force on it will simply not be accelerating. It can be in motion, but it can not have any change in its velocity.
The object remain stable in situ
WHAT THE SPEED OF STATIONARY OBJECT?
By definition, every force acting on the object affects its velocity.Newton's second law states that the acceleration of an object (the rate of change of velocity with time) is equal to the net force on the object divided by the object's mass. Force is a vector, so if you have several forces acting on the object you must take their vector sum. Only if all the forces acting on the object sum up to zero will the object not accelerate. In that case it will remain stationary if it was already stationary, or continue to move in the same speed and in the same direction as before.
c. Free fall
c is correct.
The forces acting on a stationary object are balanced. If you were to add up all the forces (taking the directions into account, you would get a total of 0. There are always forces acting on a object, such as gravity, so you cannot say that there are no forces acting on it. You can say that the forces are balanced.
If an object is stationary on a surface then the forces acting on it are the Gravitational force and the Normal force(the force of the surface pushing back against the object). Technically you could be pulling(or pushing) that object from opposite directions with equal forces and it would remain stationary. The important thing to understand is that a stationary object remains stationary so long as the net forces applied to it equal zero.
It will stay at rest.