Ch 17: Fluid MechanicsSee 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

Intro to Pressure

See all sections
Sections
Density
Intro to Pressure
Pascal's Law & Hydraulic Lift
Pressure Gauge: Barometer
Pressure Gauge: Manometer
Pressure Gauge: U-shaped Tube
Buoyancy & Buoyant Force
Ideal vs Real Fluids
Fluid Flow & Continuity Equation
Additional Practice
Bernoulli's Equation

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.
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
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?
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.)