1. The problem statement, all variables and given/known data An athlete whirls a 7.00 kg hammer tied to the end of a 1.3 m chain in horizontal chain. The hammer makes one complete revolution in 1.0 s. (A) What is the centripetal acceleration of the hammer? 51 m/s2 2. Relevant equations ac=4pi^2*r/r^2 3. The attempt at a solution I know the formula for centripetal acceleration is as above. but how is the answer 51? I put it in my calculator and did not get that... 4(3.14^2)(1.3)/1.3^2) What am i doing wrong??