1.
Q = 3 C
W = 27 J
-----------------
U = ?
W = Q*U
U = W/Q = 27J/3C = 9 V
U = 9 V
2.
U = 4,5 V
Q = 3,5 C
---------------------
W = ?
W = Q*U = 3,5C * 4,5V = 15,75 J
W = 15,75 J
3.
U = 6 V
W = 25,5 J
-----------------
Q = ?
W = Q*U
Q = W/U = 25,5J/6V = 4,25 C
Q = 4,25 C