mintak bantuannya kak.

19. °K = 333°
°C = ( 1/1 × 333° ) -273°
= 333° - 273°
= 60° C (A)

20. l mula² = 2 m
perbedaan suhu = 75° - 25°
= 50°C
koef. muai = 24 × 10^-6/°C
lt= l0(1+a (T2-T1)
lt = 2 m(1 + 24 × 10^-6/°C × 50°C)
lt = 2 m + (2 × 24 × 10^-5 × 5) m
lt = 2 m + 24 × 10^-4 m = 2,0024 m (D)

21. Q = m.c. (T2-T1)
= 500/1000 kg × 4200 J/kg°C × (70-20)°C
= 1/2 × 4200J × 50
= 105.000 J = 105 × 10³ J (E)