If the current exposure rate is 32 mR/hr, how long will it take for the exposure rate to drop to 2 mR/hr?

To determine how long it will take for the exposure rate to drop from 32 mR/hr to 2 mR/hr, we can use the concept of radioactive decay and the half-life of the radioactive material, though the question does not provide the half-life directly. However, we can reason through the situation by looking at the ratio of the initial and final exposure rates.

Starting at 32 mR/hr and aiming to reach 2 mR/hr represents a significant decrease. The ratio of the initial exposure rate to the final exposure rate is 32/2, which simplifies to 16. This means that the exposure has to decrease by a factor of 16.

In radioactive decay, the exposure rate decreases exponentially. Each half-life reduces the activity (and consequently the exposure rate) by half. To find how many half-lives are necessary to reach the desired exposure rate, we look for how many times we can halve the initial value to arrive at 2 mR/hr.

From 32 mR/hr, halving once brings us to 16 mR/hr, halving a second time brings us to 8 mR/hr, a third time to 4 mR/hr, and a fourth halving yields 2 m