Odpowiedź :
Odpowiedź:
A.
P = 1200 W
t = 15 min = 1/4 h
W = P*t
W = 1200 W * 1/4 h
W = 300 Wh = 0,3 kWh
koszt
0,3 kWh * 0,8 zł/kWh = 0,24 zł
B.
P = 1400 W
t = 1,5 min = 0,025 h
W = P * t
W = 1400 W * 0,025 h
W = 35 W = 0,035 kWh
koszt
0,035 kWh * 0,8 zł/kWh = 0, 028 zł
C.
P = 1000 W
t = 12 h
W = P*t
W = 1000 W * 12 h
W = 12000 Wh = 12 kWh
koszt
12 kWh *0,8 zł/kWh = 9,6 zł
D.
P = 80 W
t = 6 h *30 dni
W = P * t
W = 80 W * 6 h * 30 = 14400 Wh = 14,4 kWh
koszt
14,4 kWh * 0,8 zł/ kWh = 11,52 zł
E.
P = 80 W * 5 = 400 W
t = 20 dni = 20 * 24 h = 480 h
W = P * t
W = 400 W * 480 h
W = 192000 Wh = 192 kWh
koszt
192 kWh * 0,8 zł/kWh = 153,6 zł
Zadanie 2
A. 2 kWh ⇒ J
2 kWh = 2*1000 * 3600 W*s = 7200000 Ws
2 kWh = 7200000 J
B.
0,5 kWh ⇒ J
0,5 kWh = 0,5 * 1000 * 3600 W*s = 1800000 W*s
0,5 kWh = 1800000 J
C.
108000000 J ⇒ kWh
108000000 J = 108000000 Ws = 108000000 W * 1/3600 h = 30000 Wh = 30 kWh
108000000 J = 30 kWh