Question

Answer 1

\(\Rightarrow Qthu1=Qtoa1\Leftrightarrow5mc=m1c1\left(t''-t'-5\right)\left(1\right)\)

\(\Rightarrow Qthu2=Qtoa2\Leftrightarrow3mc=m1c1\left(t''-t'-8\right)\left(J\right)\left(2\right)\)

lay(1) chia (2) \(\Rightarrow\dfrac{5}{3}=\dfrac{t''-t'-5}{t''-t'-8}\)\(\Rightarrow t''=\dfrac{25+2t'}{2}\left(3\right)\)

tiep tuc do 3ca

\(\Rightarrow QTHU3=Qtoa3\Leftrightarrow\left(t'''-t'-8\right)=3m1c1\left(t''-t'''\right)\left(4\right)\)

thay (3) vao(4)\(\Rightarrow\Delta t=t'''-t'=.....^oC\)