Ch 17: Fluid MechanicsWorksheetSee all chapters
All Chapters
Ch 01: Units & Vectors
Ch 02: 1D Motion (Kinematics)
Ch 03: 2D Motion (Projectile Motion)
Ch 04: Intro to Forces (Dynamics)
Ch 05: Friction, Inclines, Systems
Ch 06: Centripetal Forces & Gravitation
Ch 07: Work & Energy
Ch 08: Conservation of Energy
Ch 09: Momentum & Impulse
Ch 10: Rotational Kinematics
Ch 11: Rotational Inertia & Energy
Ch 12: Torque & Rotational Dynamics
Ch 13: Rotational Equilibrium
Ch 14: Angular Momentum
Ch 15: Periodic Motion (NEW)
Ch 15: Periodic Motion (Oscillations)
Ch 16: Waves & Sound
Ch 17: Fluid Mechanics
Ch 18: Heat and Temperature
Ch 19: Kinetic Theory of Ideal Gasses
Ch 20: The First Law of Thermodynamics
Ch 21: The Second Law of Thermodynamics
Ch 22: Electric Force & Field; Gauss' Law
Ch 23: Electric Potential
Ch 24: Capacitors & Dielectrics
Ch 25: Resistors & DC Circuits
Ch 26: Magnetic Fields and Forces
Ch 27: Sources of Magnetic Field
Ch 28: Induction and Inductance
Ch 29: Alternating Current
Ch 30: Electromagnetic Waves
Ch 31: Geometric Optics
Ch 32: Wave Optics
Ch 34: Special Relativity
Ch 35: Particle-Wave Duality
Ch 36: Atomic Structure
Ch 37: Nuclear Physics
Ch 38: Quantum Mechanics

Concept #1: Pressure and Atmospheric Pressure

Practice: A large warehouse is 100 m wide, 100 m deep, 10 m high:
a) What is the total weight of the air inside the warehouse?
b) How much pressure does the weight of the air apply on the floor?

Concept #2: Pressure In Air and In Liquids

Concept #3: Calculating Pressure in Liquids

Practice: The deepest known point on Earth is called the Mariana Trench, at ~11,000 m (~36,000 ft). If the surface area of the average human ear is 20 cm2 , how much average force would be exerted on your ear at that depth?

Practice: A tall cylindrical beaker 10 cm in radius is placed on a picnic table outside. You pour 5 L of an 8,000 kg/m3 liquid and 10 L of a 6,000 kg/m3 liquid into. Calculate the total pressure at the bottom of the beaker.

Practice: A wooden cube, 1 m on all sides and having density 800 kg/m3 , is held under water in a large container by a string, as shown below. The top of the cube is exactly 2 m below the water line. Calculate the difference between the force applied by water to the top and to the bottom faces of the cube (Hint: calculate the two forces, then subtract).

Additional Problems
A window in a submersible needs to be able to withstand the incredible forces that water will exert at depth. If the window is 30 cm x 15 cm, what would the force exerted by the water be at a depth of 1 km? Assume that the density of sea water is 1029 kg/m3.
An open container is filled with water, to a depth of 5 cm. Above that, a layer of oil 2 cm thick is poured on top of the water. If the density of the oil is 700 kg/m3, what the pressure at the top of the oil? At the water-oil boundary? At the bottom of the container? Take atmospheric pressure to be 1x105 Pa.
In a lecture demonstration, a professor pulls apart two hemispherical, steel shells (diameter D) with ease using their attached handles. She then places them together, pumps out the air to an absolute pressure of p, and hands them to a bodybuilder in the back row to pull apart. If atmospheric pressure is p0, how much force must the bodybuilder exert on each shell? Evaluate your answer for the case p=0.025 , D=10.0 .
A cube of side s is completely submerged in a pool of fresh water. Derive an expression for the pressure difference between the bottom and top of the cube.a. Pbottom - Ptop = Pfluidgsb. Pbottom - Ptop = Pfluidsc. Pbottom - Ptop = Pcubegsd. Pbottom - Ptop = Patm + Pfluidgs
The Aswan High Dam is 111 m high. What is the absolute pressure at the foot of the dam? [A] 1.09 × 106 Pa [B] 1.09 × 103 Pa [C] 1.19 × 106 Pa [D] 1.11 × 102 Pa
The four tires of an automobile are inflated to a gauge pressure of 2.0 x 10 5 Pa. Each tire has an area of 0.024 m2 in contact with the ground. Determine the weight of the automobile.
A container is filled to a depth of 20.0 cm with water. On top of the water floats a 30.0-cm-thick layer of oil with specific gravity 0.700. What is the absolute pressure at the bottom of the container?
a) Estimate the pressure exerted on a floor by one pointed chair leg (66 kg on all four legs) of area = 2.6×10−2 cm2. b) Estimate the pressure exerted on a floor by a 1200-kg elephant standing on one foot (area = 860 cm2 ).
A patient is to be given a blood transfusion. The blood is to flow through a tube from a raised bottle to a needle inserted in the vein. The inside diameter of the 26-mm-long needle is 0.81 mm, and the required flow rate is 2.3 cm3 of blood per minute. How high h should the bottle be placed above the needle? Assume the blood pressure is 78 torr m torr above atmospheric pressure.
Intravenous infusions are often made under gravity, as shown in the figure.a) Assuming the fluid has a density of 1.00 g/cm3, at what height h1 should the bottle be placed so the liquid pressure is 58 mm-Hg ?b) At what height h2 should the bottle be placed so the liquid pressure is 660 mm-H2O ?c) If the blood pressure is 78 mm-Hg above atmospheric pressure, how high should the bottle be placed so that the fluid just barely enters the vein?
A diver wishes to recover a treasure chest she found at the bottom of the sea, 60 m below the surface. To do this, she inflates a plastic balloon to a radius of 40 cm with the air from her compressed air tanks. The mass of the treasure chest is 200 kg and its dimensions are 20 cm x 40 cm x 10 cm. Take the density of sea water as 1025 kg/m3. What is the pressure at this depth?
The lower end of a long plastic straw is immersed below the surface of the water in a plastic cup. An average person sucking on the upper end of the straw can pull water into the straw to a vertical height of 1.1 m above the surface of the water in the cup. What is the lowest gauge pressure that the average person can achieve inside his lungs?
If the gauge pressure is doubled, the absolute pressure willa. be halved.b. be doubled.c. be unchanged.d. be increased, but not necessarily doubled.e. be decreased, but not necessarily halved.
A swimming pool 6.0 m wide by 13 m long is filled to a depth of 13 m. What is the pressure on the bottom of the pool? (Express your answer to two significant figures.)
At 25°C the density of ether is 72.7 kg/m3 and the density of iodine is 4930 kg/m3. A cylinder is filled with iodine to a depth of 1.6 m. How tall would a cylinder filled with ether need to be so that the pressure at the bottom is the same as the pressure at the bottom of the cylinder filled with iodine? (Express your answer to two significant figures.)
Convert the following units of pressure to the SI unit of pascals (Pa), where 1 Pa = 1 N/m2. 2300 kPa = _____ Pa (Express your answer to two significant figures.)
Convert the following units of pressure to the SI unit of pascals (Pa), where 1 Pa = 1 N/m2. 871 torr = _____ Pa (Express your answer to three significant figures.)
A rectangular swimming pool is 8.0 m × 30 m in area. The depth varies uniformly from 1.0 m in the shallow end to 3.0 m in the deep end.Determine the pressure at the bottom of the deep end of the pool. (Express your answer to two significant figures.)
Calculate the difference in blood pressure between the feet and top of the head for a person who is 1.80 m tall. Consider a cylindrical segment of a blood vessel 2.70 cm long and 2.40 mm in diameter. What additional outward force would such a vessel need to withstand in the persons feet compared to a similar vessel in her head?