Jawabanya apa? Caranya?

m = 10 kg
t1 = 20 C
P = 2,8 kW = 2800 W
t2 = 85 C
C = 4200 J/kg C
t?

penyelesaian:
W = Q

P × t = m × C × (t2 - t1)

2800 × t = 10 × 4200 × (85 - 20)

2800t = 42000 × 65

t = 2730000 / 2800

t = 975 sekon,karena mintanya menit maka di bagi 60

t = 16 menit 25 sekon