Uji Kompetensi Bab 6, Romawi 2, no.26

     D₁ = C_a = 4200 J/kg K

              k_u  = 2,26 . 10⁶ J/kg

              m_air  = 100 gr

              T₁ = 20 ⁰ C

              Q = 2,5 . 10⁵ J = 250000 J

     D₂ =  a. T_akhir . . . . . .  ? → 100 ⁰ C

              b. m_air yang menguap . . . ?

     D₃ =  Q₁ = m_a . C_{a .} Δt

                   = 0,1 . 4200 . 80

                   = 420 . 80 = 33600 J

              Q₂ = m_a . k_u

                   = 0,1 . 2,26 . 10⁶

                   = 2,26 . 10⁵  

                   = 226000 J

              Q₁ + Q₂  > Q

              33600 + 22600 > Q

              259600 > Q

 

              (Q₁ + Q₂ ) – Q

              = 259600 – 250000

              = 9600 J

 

              ΔQ = m_a . k_u

              9600 = m_a . 2,26 . 10⁶

              9,6 = m_a . 2,26 . 10³

              m_a = 9,6 ÷ 2,26 . 10³        

              m_a = 0,0042478 kg

By: Vincent Sidharto / XJ - 37