Question

2 kg air bersuhu 20°C,dimasukkan pada 0,25 kg,diberi panas yg bersuhu 100°c ,beapa suhu keseimbangan campuran kedua tsb?
kalor jenis besi : 450 j/kg°c
masa : 0,25 kg
cair : 4200 j/kg°c

Answer 1

Q lepas = Q serap
m besi x c besi x ΔT = m air x c air x ΔT
0,25 x 450 x (100-T) = 2 x 4200 x (T-20)
112,5 (100-T) = 8400 (T-20)
11250 - 112,5T = 8400T - 168000
179250 = 8512,5T
T = 21 C

Answer 2

Q lepas = Q serap
m besi x c besi x ΔT = m air x c air x ΔT
0,25 x 450 x (100-Tf) = 2 x 4200 x (Tf-20)
112,5 (100-Tf) = 8400 (Tf-20)
11250 - 112,5Tf = 8400Tf - 168000
179250 = 8512,5Tf
Tf = 179250 : 8512,5
    = 21°C