238 The isotope of plutonium Pu is used to make thermoelectric power sources for spacecraft. Suppose that a space probe was launched in 2012 with 4.0 kg of 28P Part 1 of 2 238 (a) If the half-life of 238 Pu is 87.7 yr, write a function of the form Q(t)-etomodel the quantityof 8P left after t years. Round the value of k to five decimal places. Do not round intermediate calculations. e0.00790 Alternate Answer: 0-40e 0.00791 Part: 1/2 Part 2 of 2 (b) If 1.4 kg of 238Pu is required to power the spacecraft's data transmitter, for how long after launch would scientists be able to receive data? Round to the nearest year. Do not round intermediate calculations Scientists will be able to receive data for approximately yr.