A grindstone in the shape of a solid disk with a diameter of 0.460 m and a mass of 50.0 kg is rotating at 830 rev/min. You press an ax against the rim with a normal force of 200 N, and the grindstone comes to rest in 7.80 s. What is the work done by the ax?
A. 1.55 × 10⁴ J
B. 3.10 × 10⁴ J
C. 6.20 × 10⁴ J
D. 9.30 × 10⁴ J