Question 2: i believe it's half life decay
question 3: relative dating
Heat required to decrease the temperature of body is given as

here given that



now by above equation


now in order to evaporate water the heat is given as




so 97 g of water will evaporate from the body
Mechanical waves transfer energy<span> by inducing vibrations in a medium. </span>A mechanical wave requires an initial energy input. Once this initial energy is added, the wave travels through the medium until all the energy is transferred.