Odpowiedź :
F= 2 kN =2000 N
s=20 km =20000 m
t=30 min = 1800 s
W=?
P=?
W=F*s
W=2000*20000
W=40000000 J = 40 MJ
P=W/t
P=40000000/1800
P=22222 W = 22,2 kW
[tex]dane:\\F = 2 \ kN = 2 \ 000 \ N\\s = 20 \ km = 20 \ 000 \ m\\t = 30 \ min = 30\cdit60 \ s = 1800 \ s\\szukane:\\W = ?\\P = ?\\\\Praca:\\W = F\cdot s\\\\W = 2000 \ N\cdot20000 \ m\\\\W = 40 \ 000 \ 000 \ J = 40 \ 000 \ kJ = 40 \ MJ\\\\Moc:\\P = \frac{W}{t}\\\\P = \frac{40000000 \ J}{1800 \ s}\\\\P \approx 22 \ 222 \ W\approx 22,2 \ kW[/tex]