Odpowiedzi

2010-04-14T17:18:29+02:00
W = 2MJ = 3000000J = 3 mln J
P = 4kW = 4000W
P = W/t
t = W/P = (3 * 10⁶)/(4 * 10³) = 750 (s)

Odp. Praca będzie wykonywana 750s.
2010-04-14T17:19:48+02:00
P= W/t
t= W/P
t= 3000000/4000
t= 750s

Ta praca zostanie wykonana w 750s czyli 12,5min
2010-04-14T17:21:26+02:00
W - praca = Pt = 3 MJ = 3000000 J
P - moc = 4 kW = 4000 W
t = W/P = 3000000/4000 = 750 s = 12,5 min