* Force is a vector quantity: It has both magnitude and direction.
* Force acts over time: Force causes a change in an object's motion (acceleration) over a period of time.
* Instantaneous implies a single point in time: An "instant" has zero duration, and a force can't be applied in zero time.
What we *can* talk about are:
* Instantaneous acceleration: This is the rate of change of velocity at a specific moment in time.
* Impulsive force: This is a large force that acts over a very short period of time, like the force of a bat hitting a baseball. We often use the concept of impulse (force multiplied by time) to describe this.
Why the confusion?
The concept of an "instantaneous force" might arise from common language where we talk about "sudden" or "instant" forces. However, in physics, even seemingly instantaneous forces like a hammer hitting a nail take a small amount of time to act.
In summary: There's no such thing as an "instantaneous force" in the strict sense. Forces always act over some period of time, even if that time is very short.
