26. The total energy stored in the capacitor bank is
U =
1
2
C
total
V
2
=
1
2
(2000)(5.00
× 10
−6
F)(50000 V)
2
= 1.3
× 10
7
J .
Thus, the cost is
(1.3
× 10
7
J)(3.0 cent/ kW
·h)
3.6
× 10
6
J/ kW
·h
= 10 cents .
26. The total energy stored in the capacitor bank is
U =
1
2
C
total
V
2
=
1
2
(2000)(5.00
× 10
−6
F)(50000 V)
2
= 1.3
× 10
7
J .
Thus, the cost is
(1.3
× 10
7
J)(3.0 cent/ kW
·h)
3.6
× 10
6
J/ kW
·h
= 10 cents .