1000*1/100*400*U/(2*0.005)=
1000*1/100*400(U/(2*0.005)-1)+1000*1/100*u*u/(2*0.005),
1000*1/100*u*u/(2*0.005)=1000*1/100*9.8*1
You asked:
Solve the system of equations:\[\begin{aligned}\frac{\frac{1000 \cdot 1}{100} \cdot 400 U}{2 \cdot 0.005} &= \frac{1000 \cdot 1}{100} \cdot 400 \cdot \left(\frac{U}{2 \cdot 0.005} - 1\right) + \frac{\frac{1000 \cdot 1}{100} \cdot u u}{2 \cdot 0.005}\\\frac{\frac{1000 \cdot 1}{100} \cdot u u}{2 \cdot 0.005} &= \frac{1000 \cdot 1}{100} \cdot 9.8 \cdot 1\end{aligned}\]