# Physical meaning of average acceleration

What is the physical meaning of average acceleration?

For example, average velocity is that uniform velocity with which if an object is made to move, it will cover the same displacement in a given time interval at it does with its actual velocity in the same time.

Similarly, what is the physical meaning of average acceleration? First it seemed obvious to me, that physical acceleration is that uniform acceleration with which if an object is made to move, it will undergo the same amount of "change in velocity" in a given time interval as it does with its actual acceleration in the same time.

But acceleration is a vector quantity. So the direction of the average acceleration (same as that of change in velocity) must be same as that of final velocity when the object was moving with its actual acceleration? Assuming my understanding of physical meaning of average acceleration is correct. Am I missing something here?

Back to my question, what's the physical meaning of average acceleration?

• Displacement and velocity are vector quantities too. – J. Murray Sep 30 '18 at 14:30
• Yeah, but I think I understand it quite well, what average velocity is, its physical meaning, I mean. I've tried to explain it briefly in my post. What I'm struggling to understand is, the physical meaning of average acceleration – π times e Sep 30 '18 at 14:32
• Acceleration need not be in the same direction as the final velocity. – harshit54 Sep 30 '18 at 15:40
• I'm talking of average acceleration. And I'm pretty sure its direction (same as that of change in velocity) should be the direction of the final velocity of the object when it was moving with its actual acceleration. Otherwise, what's the point of finding out the average acceleration? If that's not the case – π times e Sep 30 '18 at 15:53

## 1 Answer

Your description of average acceleration is correct. However it is in general not true that final velocity and average acceleration point in the same direction.