Question

Answer 1

Bài 2.55

Ta có: \(Q=mc\Delta t=2\cdot4200\cdot\left(100-20\right)=672000\left(J\right)\)

 

Answer 2

Bài 2.56

Ta có: \(Q=mc\Delta t\)

\(\Rightarrow5\cdot4200\cdot\left(t-20\right)=840000\) \(\Rightarrow t=60^oC\)

Answer 3

Bài 2.57

Ta có: \(Q=Q_{nhôm}+Q_{nước}=m_{Al}\cdot c_1\cdot\Delta t+m_{nước}\cdot c_2\cdot\Delta t'\)

\(\Rightarrow Q=0,5\cdot880\cdot\left(100-25\right)+2\cdot4200\cdot\left(100-25\right)=663000\left(J\right)\)