Saturday

January 31, 2015

January 31, 2015

Posted by **Josh** on Tuesday, October 25, 2011 at 1:40am.

find the half life of a radioactive substance if 220 grams of the substance decays to 200 grams in 4 years?

- Pre Calculus -
**drwls**, Tuesday, October 25, 2011 at 2:14amLet the half life be T years

2^(-4/T) = 200/220 = 0.9091

(-4/T) log 2 = log 0.9091

-4/T = -0.1375

T = 29.1 years

**Answer this Question**

**Related Questions**

Pre Calculus - Exponential Growth and Decay Find the half-life of a radioactive ...

calculus - The rate at which an amount of a radioactive substance decays is ...

Math-Exponential Decay - A lab technician had 58 grams of a radioactive ...

Math - A radioactive substance decays according to the formula Q(t) = Q0e−...

Math - A radioactive substance decays according to the formula Q(t) = Q0e−...

Science - Radioactive substance decays so that after t years, the amount ...

Calculus-derivatives - Verify if these are correct answers. 1. The derivative of...

calculus - Carbon-14 is a radioactive substance produced in the Earth's ...

Physics - A radioactive substance decays from 2.0kg to 1.6kg in 156 days. What ...

algebra - Julie has 250 grams of a radioactive substance. The substance decays ...