Question

At a sluice gate across a rectangle channel, the upstream flow conditions are depth of 2.0 m, velocity of flow of 1.25 m/sec. The flow conditions at the vena contract just downstream of the gate can be taken as: depth of 0.44m; velocity of flow of 5.68 m/sec. What is the total thrust on the gate on its upstream face (to the nearest 10 units)?

• A. 770 kgf
• B. 825 kgf
• C. 800 kgf
• D. 870 kgf

Answer 1

The correct option is A 770 kgf

$F=\frac{\rho (y_1-y_2{)}^3}{2(y_1+y_2)}=\frac{1000}{2}\frac{(2-0.44{)}^3}{(2+0.44)}=762.39kgf\simeq 770kgf$