質問: the earth formed 4.57 x 10^9 years ago. what is this time in seconds? the earth formed 4.57 x 10^9 years ago. what is this time in seconds? 1.67\times10^{12}\;{\rm s} 4.01\times10^{13}\;{\rm s} 2.40\times10^{15}\;{\rm s} 1.44\times10^{17}\;{\rm s}
回答: 4.57*10^9 yrs * 365 days/1yr * 24 hours/1day * 60 minutes /1 hour * 60 secs/1 min. then use a calculator.