Question and Answers Forum

All Questions      Topic List

None Questions

Previous in All Question      Next in All Question      

Previous in None      Next in None      

Question Number 31954 by mondodotto@gmail.com last updated on 17/Mar/18

Answered by mrW2 last updated on 18/Mar/18

$$A=A_0{e}^{-\lambda t}$$$$0.5A_0=A_0{e}^{-15\lambda }$$$$\Rightarrow \lambda =\frac{\ln 2}{15}$$$$0.4A_0=A_0{e}^{-\lambda t}$$$$\Rightarrow \lambda t=\ln 0.4^{-1}=\ln 2.5$$$$\Rightarrow t=\frac{\ln 2.5}{\ln 2}\times 15=19.8\approx 20hours$$

Commented by mondodotto@gmail.com last updated on 19/Mar/18

$$\mathrm{thanx}$$

Terms of Service

Privacy Policy

Contact: info@tinkutara.com