Saturday

December 20, 2014

December 20, 2014

Posted by **Sue** on Saturday, August 14, 2010 at 6:57am.

The mass of a particular substance is known to grow exponentially at a rate of 1.5% per day. Its initial mass was 230 grams and, after t days, it weighed 325 grams.

The equation modelling this growth is

230×1.015 t = 325.

Use the method of taking logs to solve this equation for t, giving your answer correct to the nearest day.

- Maths -
**Reiny**, Saturday, August 14, 2010 at 8:50amI think you have a typo, and meant to say ...

230(1.015)^t = 325

(your equation would have a linear growth, not exponentially)

1.015^t = 325/230 = 1.4130435

log(1.015^t) = log 1.4130435

t = log 1.4130435/log 1.015 = 23.222

so it will take appr. 23 days.

**Answer this Question**

**Related Questions**

maths - The mass of a particular substance is known to grow exponentially at a ...

Chemistry - Assume that a reaction occurs in which unknown substances R and S ...

MATH! - The mass of a radioactive substance follows an exponential decay model, ...

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

Maths - A radioactive substance decays exponentially in such a way that after 50...

Calculus Help Please!!! - A radioactive substance has a half-life of 4 days. ...

Chemistry Help Please!!! - A radioactive substance has a half-life of 4 days. ...

chemistry - In a chemical reaction, substance A combines with substance B to ...

Chemistry - how about expressing 230 parts per thousand (ppt) of SO4^2- in mol ...

Chemistry - 1. What is the percent by mass of a solution that contains 50 grams ...