Odpowiedź :
1.
W = 20 J
t = 4s
-------------------
P ?
W = P*t
P = W/t = 20J/4s = 5 W
2.
P = 80 W
W = 40 J
-------------------
t ?
W = P*t
t = W/P = 40J/80W = 0,5 s
3.
P = 20 kW
t = 2 h
----------------------------
W ?
W = P*t = 20 kW * 2h = 40 kWh
1.
W = 20 J
t = 4s
-------------------
P ?
W = P*t
P = W/t = 20J/4s = 5 W
2.
P = 80 W
W = 40 J
-------------------
t ?
W = P*t
t = W/P = 40J/80W = 0,5 s
3.
P = 20 kW
t = 2 h
----------------------------
W ?
W = P*t = 20 kW * 2h = 40 kWh