At the beginning of an experiment a scientist has 372 grams of radioactive goo. After 165 minutes, her sample has decayed to 11.625 grams.  what is the half life of the goo in minutes? find a formula for G(t) the amount of goo remaining at time t.  G(t)=  how many grams of goo will remain after 47 minutes?

Suppose that the initial mass of radioactive substance is m0 and the half-life of the substance is h. Let m(t) be the mass remaining at time t. a What is meant by the half-life h? b Write a formula for m(t) in terms of the half-life h. c Write a formula for the relative decay rate r in terms of the half-life h. d Write a formula for m(t) in terms of the relative decay rate r.

A radiation safety officer is working with 112 grams of a radioactive substance. After 17 days, thesample has decayed to 80 grams. Rounding to fivesignificant digits, write an exponential equationrepresenting this situation. To the nearest day, whatis the half-life of this substance?

The table shows the mid-year populations (in millions) of five countries in 2015 and the projected populations (in millions) for the year 2025. (a) Find the exponential growth or decay model y=aebt or y=aebt for the population of each country by letting t=15 correspond to 2015. Use the model to predict the population of each country in 2035. (b) You can see that the populations of the United States and the United Kingdom are growing at different rates. What constant in the equation y=aebt gives the growth rate? Discuss the relationship between the different growth rates and the magnitude of the constant.