How is the equation for calculating REM expressed?

The equation for calculating REM, which stands for Roentgen Equivalent Man, is expressed as the product of radiation absorbed dose in rads and a weighting factor that accounts for the biological effect of the type of radiation on human tissue.

This weighting factor varies depending on the type of radiation (e.g., alpha particles, beta particles, gamma rays) and reflects its potential to cause biological damage. By multiplying the absorbed dose (measured in rads) by this weighting factor, the resulting value provides a more meaningful measure of the risk associated with exposure to different types of radiation. Therefore, the correct equation effectively considers both the amount of energy deposited in tissue and the potential for harm posed by the type of radiation.

In contrast, the other options do not accurately represent the relationship between absorbed dose and biological effect. For instance, dividing or adding the weighting factor does not yield a valid measure of biological risk, as this approach neglects to incorporate the full impact of the type of radiation on tissue and does not conform to established principles of radiobiology.