Dane:
P=180W
m=80g
t=50s
U=230V - napięcie sieci domowej
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a)
P=U*I
I=P/U=180W/230V ≈ 0,78 A
I=0,78 A
b)
Q = I*t = 0,78A*50s = 39 C
Q = 39 C
c)
t = 365*50s = 18 250 s
W = P*t = 180W*18250s = 3 285 000 J = 3,285 MJ
d)
W = P*t =0,180kW*20h = 3,6 kWh
cena = 80 gr za 1 kWh
Koszt = W*cena = 3,6kW * 80gr/kWh = 288 gr = 2 zł 88 gr