Answer:
a) P = 1028.6 W = 1.03 KW
b) Cost = $0.25
Explanation:
a)
The rate of electrical energy transfer or power of the heater is given as:
P = VI
where,
P = Rate of Electrical Energy Transferred = ?
V = Potential Difference = 120 V
I = Current
but, from Ohm's Law:
V = IR
I = V/R
Therefore,
P = V²/R
where,
R = Resistance = 14 Ω
Therefore,
P = 120²/14
P = 1028.6 W = 1.03 KW
b)
First we find energy used:
Energy = E = Pt
where,
t = time = 5 h
Therefore,
E = (1.03 KW)(5 h)
E = 5.14 KWh
Now, the cost is given as:
Cost = (E)(Unit Price)
Cost = (5.14 KWh)($0.05/KWh)
Cost = $0.25