Here's an example that I've used in introductory lectures: Imagine that you are in spaceship high above the plane of the solar system and you take a "snap shot" that includes both the sun and the planet Jupiter. Knowing the scale, you could use that snap shot to determine the distance from the sun to Jupiter at that instant. And, then, using Newton's gravity formula, you could calculate the force the sun exerts on Jupiter and so Jupiter's acceleration at that instant.
But what does "acceleration at a specific instant" mean? Acceleration is defined as "change in speed over change in time" and speed itself is defined as "change in distance over change in time". Both of those require a "change in time" and so make no sense "at a specific instant". That was the problem that Newton faced in developing his formula for gravitational force and he created Calculus to solve it!