just do T2-2 please

T2-2 (7.5 Points): In a room of constant temperature A = 20C, a container with cooling constant k = 0.1 is poured 1 gallon of boiling water at TB = 100C at time t = 0. Waiting till t = 10, I add 5 gallons of icey water Tlce = 0C to the container, rapidly (ignoring pouring time). Compute the water temperature at t = 15. Hints:- lee temperature ofmI'XI'Hgml gallons of water atTl with m2 gallons at T2 is (m1T1 + m2T2)/(m1 + m2) T2-1 (7.5 Points) In a tea house at a constant temperature A = 90F, I brewed a cup of tea with hot water whose temperature was To = 210F. I waited for 15 minutes, after pouring the hot water, to measure the tea's temperature and it's T15 = 150F. I want to drink the tea at precisely Tx = 105F. How much longer should I wait? Consider the Newton's cooling law: dT - k(A T) dt _ T(t = 0) = T0 We can get the solution 1 T A For the rst 15 minutes,A = 90F, T0 = 210F, T15 = 150F, 1315 = 15, we have 15_ 11 (TlsA)_ 11 (15090)_ 11 (60)_11(2) ' kn ToA _ kn 21090 ' kn 120 _kn During the waiting tx minutes, A = 90F, T15 = 150F, Tx = 105F, we have t _ 11 (TrA)_ 11(10590)_ 11 (15)_21(2) \"- knTlsA _ k" 15090 _ kn 60 _kn Thus, tx = 30. So, you need to wait for 30 more minutes