The sunlight that reaches the outer solar system is too feeble to power a spacecraft with solar panels. Space probes like Cassini, sent to explore Saturn and its moons, use a radioisotope thermoelectric generator (RTG), which converts the heat generated from radioactive decay to electricity. The RTG on Cassini (Fig. P30.90) generates 13 kW of heat using 23.4 kg of ²³⁸Pu, which emits an alpha particle with 5.6 MeV of kinetic energy upon each decay. 

(a) Estimate the activity in units of Bq and Ci contained in the RTG. 

(b) Cassini was designed for an 11-yr mission. If the half-life of ²³⁸Pu is 87.7 yr, how much power will be available from the RTG at the very end of the mission?