Exam 12: Fluid Mechanics

Water,of density 1000 kg/m³,is flowing in a drainage channel of rectangular cross-section.The width of the channel is 15 m,the depth of the water is 8.0 m and the speed of the flow is .At what rate is water flowing in this channel?

A 12,000-N car is raised using a hydraulic lift,which consists of a U-tube with arms of unequal areas,filled with incompressible oil and capped at both ends with tight-fitting pistons.The wider arm of the U-tube has a radius of and the narrower arm has a radius of .The car rests on the piston on the wider arm of the U-tube.The pistons are initially at the same level.What is the initial force that must be applied to the smaller piston in order to start lifting the car? (For purposes of this problem,you can neglect the weight of the pistons.)

In the figure,an open tank contains a layer of oil floating on top of a layer of water (of density that is 3.0 m thick,as shown.What must be the thickness of the oil layer if the gauge pressure at the bottom of the tank is to be The density of the oil is .

The small piston of a hydraulic lift has a diameter of 8.0 cm,and its large piston has a diameter of 40 cm.The lift raises a load of 15,000 N. (a)Determine the force that must be applied to the small piston. (b)Determine the pressure applied to the fluid in the lift.

A 12,000-N car is raised using a hydraulic lift,which consists of a U-tube with arms of unequal areas,filled with incompressible oil with a density of 800 kg/m³ and capped at both ends with tight-fitting pistons.The wider arm of the U-tube has a radius of 18.0 cm and the narrower arm has a radius of 5.00 cm.The car rests on the piston on the wider arm of the U-tube.The pistons are initially at the same level.What is the force that must be applied to the smaller piston in order to lift the car after it has been raised 1.20 m? (For purposes of this problem,you can neglect the weight of the pistons.)

A 50-cm³ block of wood is floating partially submerged in water,and a 50-cm³ block of iron is totally submerged in water.Which block has the greater buoyant force on it?

A rock is under water in a shallow lake.As the rock sinks deeper and deeper into water,the buoyant force on it

In a section of horizontal pipe with a diameter of 3.00 cm the pressure is 5.21 kPa and water is flowing with a speed of 1.50 m/s.The pipe narrows to 2.50 cm.What is the pressure in the narrower region if water behaves like an ideal fluid of density 1000 kg/m³?

A horizontal tube consists of a pipe that narrows to a 2.0-cm-diameter throat.In the pipe,the water pressure is twice atmospheric pressure and the water flows with a speed of What is the pressure in the throat,assuming that the water behaves like an ideal fluid? The density of water is 1000 kg/m³,and atmospheric pressure is .

A rock is suspended from a scale reads 20.0 N.A beaker of water (having a density of 1000 kg/m³)is raised up so the rock is totally submerged in the water.The scale now reads .What is the density of the rock?