What id an instantaneous accelaration mean?

Answer 1

It means acceleration at a specific instant of time. You can calculate the average acceleration by dividing change of velocity, by the time during which this changes. If you take smaller and smaller times, dividing change of velocity by a small time interval in every case, you can imagine approaching the "true" acceleration.

Answer 2

Acceleration is the rate of change in velocity.

If the rate of acceleration is constant then it can be calculated as the change in velocity divided by the time over which the change takes place. However, if the acceleration is continuously changing - in circular motion at uniform speed, for example - then the acceleration has to be calculated as the change in velocity between two moments in time which are very very close together divided by the very very small difference in time. In fact, it is calculated as the limit of this ratio as the different in times tends to zero. It is the derivative of velocity with respect to time.

Answer 3

Instantaneous acceleration refers to the acceleration of an object at a specific moment in time. It is the rate at which the velocity of an object changes at a single instant, giving information about how quickly the speed or direction of the object is changing. Unlike average acceleration, which is calculated over a period of time, instantaneous acceleration provides insight into the object's motion at a precise point in time.