Question 1: The attenuateon in tissues is commonly described in terms of the half value layer (HVL), defined as the thickness of the material at which the intensity of radiation entering it is reduced by one half. (a) Determine the relationship between the attenuateon coefficient and the HVL.

(b) if the thickness of a torso is 20 cm, which percentage of X-rays is transmitted through it for an incident beam of 70 Kev, assuming HVL values of 3.5 and 1.8 cm for soft and hard tissues respectively, and a thickness of 4 and 16 cm of hard and soft tissues respectively?