1. The problem statement, all variables and given/known data A hawk flies in a horizontal arc of radius 13.5 m with a speed of 3.9 m/s. What is its centripetal acceleration? (I correctly found this to be 1.1267 m/s².) Next question is: If it continues to fly along the same horizontal arc but increases its speed at a rate of 0.54 m/s², what is the magnitude of acceleration under these new conditions? 2. Relevant equations Centripetal acceleration = v² / r; possibly another one or two. 3. The attempt at a solution Finding the first half of this was easy enough, as 3.9² / 13.5 = 1.1267. But I have tried three different ways of incorporating this acceleration and have gotten it wrong each time. The only other thing I can think of trying is using the circumference of this path as displacement, finding its velocity (10.335 after one "lap"), and using that to find a new acceleration, but I'd rather not blow any more answer submissions on this one question. By the above, I'm coming up with 7.913 m/s². Am I on the right track, or am I making this way too difficult?