Odpowiedź:
7.
P=2000W = 2kW
t=40min = [tex]\frac{2}{3}[/tex] h
t= 40 min = 2400s
W = P × t
W = 2kW × [tex]\frac{2}{3}[/tex] h = [tex]\frac{4}{3}[/tex] kWh = 1,3kWh
W = 2000 W * 2400s = 4800000J
8.
W=?
t = 1min = 60s
I = 2,5 A
R = 92
W = U * I * t
R= [tex]\frac{U}{I}[/tex]
U = R * I
W = R* I * I * t
W= 92 * 2.5 * 2.5 * 60 = 34500J= 34,5kJ
Wyjaśnienie:
