Problem 3.52 - A y p d = 2 L cos ( ) y y g y sin ( ) w d =...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Problem 3.52 [Difficulty: 3] Given: Geometry of plane gate W h L = 3 m dF y L /2 w = 2 m Find: Minimum weight to keep it closed Solution: Basic equation F R A p d = dp dh ρ g = Σ M O 0 = or, use computing equations F R p c A = y' y c I xx Ay c + = Assumptions: static fluid; ρ = constant; p atm on other side; door is in equilibrium Instead of using either of these approaches, we note the following, using y as in the sketch Σ M O 0 = W L 2 cos θ () F y d = We also have dF p dA = with p ρ g h = ρ g y sin θ () = (Gage pressure, since p = p atm on other side) Hence W 2 L cos θ ()
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: A y p d = 2 L cos ( ) y y g y sin ( ) w d = W 2 L cos ( ) A y p d = 2 g w tan ( ) L L y y 2 d = 2 3 g w L 2 tan ( ) = Using given data W 2 3 1000 kg m 3 9.81 m s 2 2 m 3 m ( ) 2 tan 30 deg ( ) N s 2 kg m = W 68 kN =...
View Full Document

Ask a homework question - tutors are online