Jawaban:
1) Dik:
L₀ = 1000 cm
ΔT = 40°C
α = 1,2 x 10⁻⁵ /°C (lihat tabel)
Dit: ΔL = ?
Jwb: ΔL = L₀.α.ΔT
= 1000. 1,2. 10⁻⁵. 40
= 0,48 cm
2) Dik:
m₁ = 0,5 kg, T₁ = 100°C,
c₁ = 4200 J/kg°C
m₂ = 1 kg, T₂ = 25°C,
c₂ = 900 J/kg/°C
Dit: Tc (suhu campuran/kesetimbangn) = ?
Jwb:
Q₁ = Q₂
m₁c₁ΔT₁ = m₂c₂ΔT₂
0,5. 4200. (100 - Tc) = 1. 900. (Tc - 25)
Kedua ruas dibagi 100,
21(100 - Tc) = 9(Tc - 25)
2100 - 21Tc = 9Tc - 225
2100 + 225 = 9Tc + 21Tc
2325 = 30Tc
Tc = 2325/30
= 77,5°C