The time intervals are missing in the question.You can put any time in equation v(t) which I have solved
Answer:

Step-by-step explanation:
Given data
Velocity=52 m/s
Height h(t)=52t-0.83t²
To find
Average velocity
Solution
As we know that velocity is first derivative of distance with respect to time
So
![v(t)=(dh(t))/(dt)\\ v(t)=(d)/(dt)[52t-0.83t^(2) ]\\ v(t)=52-1.66t](https://img.qammunity.org/2021/formulas/physics/college/vzavt83ppqbajyu766td4rce1byiqvf460.png)
After one second the velocity is