A dead body was found within a closed room of a house where the temperature was a constant 70° F. At the time of discovery the core temperature of the body was determined to be 90° F. One hour later a second measurement showed that the core temperature of the body was 85° F. Assume that the time of death corresponds to  t = 0  and that the core temperature at that time was 98.6° F. Determine how many hours elapsed before the body was found. [Hint: Let  t1 > 0  denote the time that the body was discovered.] (Round your answer to one decimal place.)

Radium-226 is radioactive and has a half life of 1600. years. What percentage of a sample would be left after 7.01 × 10³ years? Round your answer to 2 significant digits. % x10 5 ? olo

Q3. Identify three sources of radiation that have a significant effect on your own total exposure. How could you protect yourself against these sources? (2 Three sources that had significant effect on my exposure are: 1. Terrestrial radiation 2. Medical 3. Cosmic radiation The overall level of terrestrial radiation is relatively low and is unlikely to affect human being. As of medical purposes, I need to be more cautious in doing X-ray procedures. As much as possible keeping myself healthy all the time. As for cosmic rays, these are passing through us at this very moment, are not harmful to us or any other life on the surface of Earth

Thank you for the help!