Question

A thermometer is removed from a room where the temperature is 70° F and is taken outside, where the air temperature is 40° F. After one-half minute the thermometer reads 60° F. What is the reading of the thermometer (in degrees Ferinheight) at t = 1 min?  (Round your answer to two decimal places.)

How long (in minutes) will it take for the thermometer to reach 45° F? (Round your answer to two decimal places.)

Answer 1

* Given that :- The toom temperature ... cor temperature Mhe. of = 40° F The Temparative after 142 min = 60°F 80 tel Min temparakve - ? Tlt) =- Ts + cockt Ts = 40°F . TÓ) - Too) = 40+ cieko - 40+ then, C=30 TH) = 40+30 Cht T45) = GOOF 60 - 40+30 ok. 1510 20180 ek.15700 An 1913 )a K 1510

Ko 10115 8s (/3) R = 283 On 93) That is from of T(t) = 40+20 203 16 (013] : 40+0 elen 1932)+ + 40+30 23ht Tht) = 40+20 (2)]@t There fore at t=1 T() = 40 +30 ula = 40+ 6012 = 40 + 13.33 TW) = 53-33 (at 45° = Tto) = 40+30141 Jto 5-30-'144) 70 Is [ye) - to In 1949) ito alm[%), = -1.794 In 14/0) -0-8109 • Qao 80-2)