Exam 13: Fluids

A horizontal pipe of 50 cm² cross-sectional area carries a fluid of unknown density at a speed of 3.0 m/s. This pipe feeds a smaller pipe of cross section 25 cm². If the pressure difference between the two sections of pipe is 9000 Pa, find the density of the fluid.

At what depth in sea water is the gauge pressure equal to 1 atm? The density of sea water is 1.03 $\times$ 10³ kg/m³.

An air-conditioning system is designed to fill a room of 10 m $\times$ 8 m $\times$ 6 m with fresh air every 20 minutes. If the circular air duct has a diameter of 13 cm, calculate the speed of airflow in the duct.

A horizontal pipe of 30 cm² cross-sectional area carries water at a speed of 2.5 m/s. This pipe feeds a smaller pipe of cross section 10 cm². Find the speed of water flow in the smaller pipe.

If the atmosphere were compressed until it had the density of water, it would cover Earth to a depth of about

A flat plate with a negligible mass and an area of 1.0 cm² is placed in a horizontal position well beneath the surface in a liquid that is not moving. The pressure at the location of the plate is P Pa. The total force that arises from the pressure of the liquid on this plate is

A rock of mass M, that has a density twice that of water, is suspended in water by a thin, massless cord. The tension in the cord is

A wind with speed 45 m/s blows across a roof 20 m long and 12 m wide. The pressure inside the room is 1 atm. What is the net force on this roof due to the pressure difference inside and outside the roof? (The density of air is equal to 1.3 kg/m³.)

You are floating in a boat in a swimming pool. The boat contains some blocks of wood. The specific gravity of the wood is 0.66. You throw the wood blocks into the pool. When the waves settle, the depth of the water in the pool

What is the gauge pressure at a depth of 6 cm in a glass filled with 4 cm of mercury and 4 cm of water? Water has a density of 1000 kg/m³, and mercury has a density 13.6 times as great.

A large tub is half full of water. A mass M = 25.0 kg, which has a specific gravity of 2.5, is attached to the right-hand side of the tub, out of the water. The entire apparatus balances perfectly horizontally on a fulcrum at F, as in (a). The tub is clamped in place and M is lowered to the bottom, completely submerged, as in (b). When the clamps are removed, the tub