A 6-kg brass ball whose specific heat is 0.40 kJ/kg.°C is brought in to a room filled with saturated steam at 90°C. The temperature of the ball rises from 20°C to 90°C while some steam condenses on the ball as it loses heat (but it still remains at 90°C). The mass of steam that condensed during this process is

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m_ball=6 "kg"
T=90 "C"
T1=20 "C"
T2=90 "C"
Cp=0.4 "kJ/kg.C"
Q=m_ball*Cp*(T2-T1)
Q=m_steam*h_fg "kJ"
h_f=ENTHALPY(Steam_ IAPWS, x=0,T=T)
h_g=ENTHALPY(Steam_ IAPWS, x=1,T=T)
h_fg=h_g-h_f
"Some Wrong Solutions with Common Mistakes:"
Q=W1m_steam*h_g "Using h_g" 
Q=W2m_steam*4.18*(T2-T1) "Using m*C*DeltaT = Q for water"
Q=W3m_steam*h_f "Using h_f"

A 6-Kg Brass Ball Whose Specific Heat Is 0