1. The problem statement, all variables and given/known data "A cup of hot chocolate, in a room temperature of 21*C, cools accordiing to Newton's law of cooling. Determine the rate of cooling, k, of the hot chocolate if it cools from 86*C to 65*C in 15 minutes" 2. Relevant equations Newton's cooling law, ln function T-Ts=(T. - Ts)e^(kt) 3. The attempt at a solution T-Ts=(T. - Ts)e^(kt) 65-21=(86-21)e^(15k) 44=65e^(15k) 44/65=e^(15k) ln(44/65)=15k (ln(44/65))/15=k k=-0.02601... Is this right?