Tolong ya kak jawab soal no 41 ini. So i'm really confused

KALOR
+ LISTRIK

R = 10 ohm
i = 10 A

m/t = 50 gr/s
c = 1 kal/gr°C = 4,2 J/(gr °C)
1 kal = 4,2 J
ta = 15 °C ← ANGGAP
tb = ___?

W listrik = Q air
i² R t = m c ∆t
i² R = (m/t) c (tb - ta)
10² • 10 = 50 • 4,2 • (tb - 15)
1000 = 210 (tb - 15)
tb - 15 = 1000/210
tb - 15 = 4,76
tb = 15 + 4,76
tb = 19,76 °C ← jwb