Step-by-step explanation:
30 minutes is 1800 seconds.
Power = energy / time
P = 1100 J / 1800 s
P = 0.611 W
Converting the energy from J to kWh:
1100 J × (1 Ws / 1 J) × (1 kW / 1000 W) × (1 h / 3600 s) = 3.06×10⁻⁴ kWh
To find resistance, you need to be given either the voltage or the current.