Oil (S =0.8)

1. Ce 3502 In class mid sem. quiz, Oct 11, 2007: Open Book/Note Answer on Exam sheet Name: A tank contains water at a depth of 1.5 m overlaid with an Oil layer (S =0.8) of thickness 0.5 m. A hinged gate of dimension 1m x 1m is placed on the right vertical side of the tank, the hinge is 0.5m below the WATER surface 0.5m Oil (S =0.8) 0.5m Water ycp 1.5m F • Determine • the pressure Force acting on the fluid side of the gate • Force is pressure at gate centroid Pc x area of gate A = 1 x 1 = 1 • Centroid is a depth of 1 m in the water so Pressure at centroid is • The vertical line of action of this force ycp --- measured down from the HINGE • The apparent WATER depth of the centroid is h = 0.5*0.8+1 = 1.4 m • The distance of the line of action below the hinge is • c. The minimum value of the Force F (applied at the bottom of the gate) to keep • the gate closed • Taking moments about the Hinge F x 1 = Fp x 0.56 = 7691 N

2. Ce 3502 In class mid sem. quiz, Oct 11, 2007: Open Book/Note Answer on Exam sheet Name: Q=1 m3/s h 0.5 m diameter Water at 10 0C enters a large tank through a horizontal pipe on the left with discharge Q = 1 m3/s and exits through a vertical bottom pipe (of diameter D =0.5 m) with an Average velocity of where h is the height of water in the tank.. • At steady state what is the height of water in the tank? • At steady state Qhorz = Qvert, 1 = VA, or • b. When the height of water in the tank is h = 0.5 m, what is the rate of mass increase? At h = 0.5 accumulation [m3/s]= Qhorz – Qvert, i.e., So mass accumulation is r x acc = 385 kg/s