P = F/S
F = mg
m = рV
V = Sh
р = 2600 кг/v^3
Подставiм:
P = рShg/S
Sh = PS/рg
1,5h = 104 000*1,5/2600*10 = 6
h = 4 => V = Sh = 1,5*4 = 6м^3
F тр=mV^2/R=1500*10^2/50=3000 H =3 кН, здесь 36 км/ч=10 м/c
E=N*dФ/dt
dФ=dB*S/dt
E=N*dB*S/dt
B=dB=E*dt/N*S=0,5*0,1/50*100*10^-4=0,1 Тл
Дiно: m = 0.5 kg; h = 10m; Ek — ?
Ek = Ep = mgh = 0.5*10*10 = 50Дж