Angular Momentum and Its Conservation (Problem 18)

Earth has a mass of 6.0 × 1024 kg, a radius of 6.4 × 106 m, and a rotational frequency of 1.2 × 10–5 rev/s. How would the planet's rotational frequency change if a layer of Earth with mass 1.0 × 1023 kg broke off of the Earth, decreasing Earth's radius by 0.2 × 106 m? Assume no friction.