Question

me ajudem na questão 1 ,2 e 3 pf

Answer 1

1)
$P = 4400 \ W = 4,4 \ kW \\ \Delta t = 0,4 \ h \\ E = P \times \Delta t = 1,76 \ kWh \\ 1 \ kWh = 3,6 \times 10^{6} \ J \\ E = 1,76 \times 3,6 \times 10^{6} \ J \\ E = 6,336 \times 10^{6} \ J$
1.1)
$Despesa = E \times 0,904 \ = 1,76 \times 0,904 = 1,59 \ reais$

2)
a)
$E_{total} = E_{util} + E_{dissipada} \\ E_{dissipada} = E_{total} - E_{util} E_{dissipada} = 4000 - 1000 = 3000 \ J$
b)
$\eta = \frac{E_{util}}{E_{total}} = \frac{1000}{4000} = 0,25 = 25 \%$