Chapter 19, Problem 19.101CP

Interpretation Introduction

Interpretation:

Determination of the amount of $Pu{O}_2$ left when the spacecraft landed on Pluto, and thus determine the power output when the spacecraft landed on Pluto

Concept introduction:

From Half-life the decay constant can be calculated as-

$\lambda =\frac{0.693}{t_{1/2}}$

$\lambda =\frac{1}{t}\ln \left(\frac{A_o}{A_t}\right)$ is 1^st order reaction

$\begin{array}{l}Powerdissipated \alpha amountof Pu present\\ P\alpha A\end{array}$

Given:

Electronic systems launched on January 19, 2006
Electronic system reached Pluto on July 14, 2015
Mass of $Pu{O}_2$ on board =11 kg
Power provided by generator when spacecraft was launched = 240 W
Half-life of $Pu$ = 87.7 y

To determine:

Power output when the spacecraft reaches Pluto