Answer:
The radius of curvature is 979 meter
Step-by-step explanation:
We have given velocity of the canon ball v = 98 m/sec
Acceleration due to gravity

We know that at highest point of trajectory angular acceleration is equal to acceleration due to gravity
Acceleration due to gravity is given by
, here v is velocity and r is radius of curvature
So

r = 979 meter
So the radius of curvature is 979 meter