To solve this problem, we can use the formula:
Q = m * c * ΔT
where Q is the heat energy transferred to the water, m is the mass of the water, c is the specific heat capacity of water, and ΔT is the change in temperature of the water.
We can first calculate the heat energy transferred to the water by the electric heater:
Q = V * I * t
where V is the voltage of the electric heater, I is the current passing through it, and t is the time the current is applied.
Q = 12 V * 5 A * 30 minutes * 60 seconds/minute Q = 10800 J
Now we can use this heat energy and the known values of m and c to calculate the change in temperature of the water:
Q = m * c * ΔT
ΔT = Q / (m * c)
ΔT = 10800 J / (0.45 kg * 4200 J/kg*K)
ΔT = 5 K
So the final temperature of the water is:
final temperature = initial temperature + ΔT
We don’t know the initial temperature of the water, so we can’t calculate the final temperature exactly. But we can say that the temperature will increase by 5 degrees Celsius (or 5 Kelvin) due to the heat energy transferred by the electric heater.