Deck 12: Fluids in Motion

Question 1

In a section of horizontal pipe with a diameter of 3.0 cm,the pressure is 100 kPa and water is flowing with a speed of 1.5 m/s.The pipe narrows to 2.0 cm.What is the pressure in the narrower region? Treat the water as an ideal incompressible fluid.

A)95 kPa
B)48 kPa
C)44 kPa
D)230 kPa
E)67 kPa

Answer 1

A

Question 2

An ideal incompressible fluid flows at 12 m/s in a horizontal pipe.If the pipe widens to twice its original radius,what is the flow speed in the wider section?

A)12 m/s
B)6.0 m/s
C)4.0 m/s
D)3.0 m/s

Answer 2

D

Question 3

Water flowing through a cylindrical pipe suddenly comes to a section of pipe where the diameter decreases to 86% of its previous value.If the speed of the water in the larger section of the pipe was what is its speed in this smaller section if the water behaves like an ideal incompressible fluid?

A)43 m/s
B)37 m/s
C)28 m/s
D)24 m/s

Answer 3

A

Question 4

Fluid flows at 2.0 m/s through a pipe of diameter 3.0 cm.What is the volume flow rate of the fluid?

A)1.4 × 10^-3 m³/s
B)5.7 × 10^-3 m³/s
C)14 m³/s
D)57 m³/s

Question 5

For a certain patient,the build-up of fatty tissue on the wall of an artery has decreased the arterial radius by 10%.By how much would the pressure provided by the heart have to be increased to maintain a constant volume of blood flow? Model the blood as an ideal incompressible fluid.

A)48%
B)52%
C)46%
D)54%

Question 6

Water is flowing in a drainage channel of rectangular cross-section.The width of the channel is 15 m,the depth of water is 8.0 m,and the speed of the flow is 2.5 m/s.What is the mass flow rate of the water? The density of water is 1000 kg/m³.

A)2.0 × 10⁵ kg/s
B)2.0 × 10³ kg/s
C)3.0 × 10⁵ kg/s
D)3.0 × 10³ kg/s
E)3.0 × 10² kg/s

Question 7

Ideal incompressible water flows through a horizontal pipe of cross-sectional area 10.0 cm² at a pressure of 0.250 atm with a volume flow rate of 1.00 × 10^-3 m³/s.At a valve,the effective cross-sectional area of the pipe is reduced to 5.00 cm².What is the pressure at the valve?

A)0.112 atm
B)0.157 atm
C)0.200 atm
D)0.235 atm

Question 8

An incompressible ideal fluid flows steadily through a pipe that has a change in diameter.The fluid speed at a location where the pipe diameter is 8.0 cm is 1.28 m/s.What is the fluid speed at a location where the diameter has narrowed to 4.0 cm?

A)0.32 m/s
B)0.64 m/s
C)1.3 m/s
D)2.6 m/s
E)5.1 m/s

Question 9

Water,which we can treat as ideal and incompressible,flows at 12 m/s in a horizontal pipe with a pressure of 3.0 × 10⁴ Pa.If the pipe widens to twice its original radius,what is the pressure in the wider section?

A)3.0 × 10⁴ Pa
B)4.9 × 10⁴ Pa
C)7.4 × 10⁴ Pa
D)9.8 × 10⁴ Pa

Question 10

Ideal incompressible fluid flows through a 4.0-cm-diameter pipe at 1.0 m/s.There is a 2.0 cm diameter constriction in the line.What is the speed of the fluid in this constriction?

A)0.25 m/s
B)0.50 m/s
C)2.0 m/s
D)4.0 m/s

Question 11

Water flows through a pipe.The diameter of the pipe at point B is larger than at point A.Where is the water pressure greatest?

A)at point A
B)at point B
C)It is the same at both A and B.

Question 12

Water flows through a horizontal pipe of cross-sectional area 10.0 cm² at a pressure of 0.250 atm with a flow rate is 1.00 L/s.At a valve,the effective cross-sectional area of the pipe is reduced to 5.00 cm².What is the pressure at the valve? The density of water is 1000 kg/m³,and treat it as an ideal incompressible fluid.

A)0.110 atm
B)0.235 atm
C)0.200 atm
D)0.157 atm
E)7700 Pa

Question 13

Two horizontal pipes are the same length,but pipe B has twice the diameter of pipe A.Water undergoes viscous flow in both pipes,subject to the same pressure difference across the lengths of the pipes.If the flow rate in pipe A is Q = ,what is the flow rate in pipe B?

A)2Q
B)4Q
C)8Q
D)16Q
E)Q

Question 14

Ideal incompressible water is flowing in a drainage channel of rectangular cross-section.At one point,the width of the channel is 12 m,the depth of water is 6.0 m,and the speed of the flow is 2.5 m/s.At a point downstream,the width has narrowed to 9.0 m,and the depth of water is 8.0 m.What is the speed of the flow at the second point?

A)2.0 m/s
B)2.5 m/s
C)3.0 m/s
D)3.5 m/s
E)4.0 m/s

Question 15

Consider a very small hole in the bottom of a tank that is in diameter and filled with water to a height of Find the speed at which the water exits the tank through the hole.

A)4.20 m/s
B)17.64 m/s
C)44.1 m/s
D)48.3 m/s

Question 16

A pump uses a piston of 15 cm diameter that moves at 2.0 cm/s as it pushes a fluid through a pipe.What is the speed of the fluid when it enters a portion of the pipe that is 3.0 mm in diameter? Treat the fluid as ideal and incompressible.

A)50 m/s
B)50 cm/s
C)6.0 cm/s
D)22 cm/s

Question 17

Two horizontal pipes have the same diameter,but pipe B is twice as long as pipe A.Water undergoes viscous flow in both pipes,subject to the same pressure difference across the lengths of the pipes.If the flow rate in pipe B is Q = what is the flow rate in pipe A?

A)2Q
B)4Q
C)8Q
D)16Q
E)Q

Question 18

A hole of radius 1.0 mm forms in the bottom of a very large water storage tank that holds water to a depth of 15 m.At what volume rate will water flow out of the hole?

A)5.4 × 10^-4 m³/s
B)5.4 × 10^-5 m³/s
C)5.4 × 10^-6 m³/s
D)5.4 × 10^-7 m³/s

Question 19

An ideal incompressible fluid flows at 0.252 m/s through a 44-mm diameter cylindrical pipe.The pipe widens to a square cross sectional area that is 5.5 cm on a side.Assume steady flow throughout the system.
(a)What is the speed of the fluid through the square section of pipe?
(b)What is the flow rate in liters per minute?

Question 20

When you blow some air above a paper strip,the paper rises.This happens because

A)the air above the paper moves faster and the pressure is higher.
B)the air above the paper moves faster and the pressure is lower.
C)the air above the paper moves faster and the pressure remains constant.
D)the air above the paper moves slower and the pressure is higher.
E)the air above the paper moves slower and the pressure is lower.

Question 21

A large cylindrical water tank 11.5 m in diameter and 13.5 m tall is supported with its base 8.75 m above the ground by a stand as shown in the figure.The water level in the tank is 10.6 m deep,and the density of the water in the tank is 1.00 g/cm³.A very small hole is formed at the base of the vertical wall of the tank,and water is squirting out of this hole horizontally.When this water hits the ground,how far has it traveled horizontally from the hole,assuming no air resistance?

Question 22

As shown in the figure,water (density 1000 kg/ )is flowing in a pipeline.At point 1 the water speed is Point 2 is 5.20 m above point 1.The cross-sectional area of the pipe is 0.0800 at point 1 and at point 2.What is the pressure difference between points 1 and 2? Treat the water as an ideal incompressible fluid.

Question 23

Water flows out of a large reservoir through 5.0-cm diameter pipe.The pipe connects to a 3.0-cm diameter pipe that is open to the atmosphere,as shown in the figure.What is the speed of the water in the 5.0-cm pipe? Treat the water as an ideal incompressible fluid.

A)2.3 m/s
B)3.2 m/s
C)3.9 m/s
D)8.9 m/s
E)10 m/s

Question 24

A fluid is flowing with an average speed of 1.5 m/s through a tube that has a radius of 2.0 mm and is 18 cm long.The drop in pressure is 967 Pa.What is the viscosity of the fluid?

A)0.0018 N ∙ s/m²
B)0.0056 N ∙ s/m²
C)0.028 N ∙ s/m²
D)0.013 N ∙ s/m²
E)0.0034 N ∙ s/m²

Question 25

Glycerin,with a viscosity of 1.5 N ∙ s/m²,is flowing with an average speed of 1.2 m/s through a tube that has a radius of 5.0 mm and is 25 cm long.What is the drop in pressure over the length of this pipe?

A)140 kPa
B)46 kPa
C)72 kPa
D)76 kPa
E)130 kPa

Question 26

A pressurized cylindrical tank,5.0 m in diameter,contains water that emerges from the pipe at point C with a speed of as shown in the figure.Point A is 10 m above point B and point C is 3.0 m above point B.The area of the pipe at point B is and the pipe narrows to an area of at point C.Assume that the water is an ideal fluid in laminar flow.The density of water is 1000 kg/m³ The mass flow rate in the pipe is closest to

A)520 Kg/s.
B)470 Kg/s.
C)420 Kg/s.
D)360 Kg/s.
E)310 Kg/s.

Question 27

Motor oil,with a viscosity of 0.25 N ∙ s/m²,is flowing through a tube that has a radius of 5.0 mm and is 25 cm long.The drop in pressure is 300 kPa.What is the volume of oil flowing through the tube per second?

A)0.00038 m³/s
B)0.025 m³/s
C)0.0012 m³/s
D)4.7 m³/s
E)7.5 m³/s

Question 28

Motor oil,with a viscosity of 0.25 N ∙ s/m²,is flowing through a tube that has a radius of 3.0 mm and is 1.0 m long.The drop in pressure over the length of the tube is 200 kPa.What is the average speed of the oil?

A)0.80 m/s
B)0.90 m/s
C)1.0 m/s
D)1.1 m/s
E)1.2 m/s

Question 29

Water flows out of a large reservoir through an open pipe,as shown in the figure.What is the speed of the water as it comes out of the pipe?

A)8.9 m/s
B)9.9 m/s
C)13 m/s
D)14 m/s
E)16 m/s

Question 30

A pressurized cylindrical tank,5.0 m in diameter,contains water that emerges from the pipe at point C with a speed of as shown in the figure.Point A is 10 m above point B and point C is 3.0 m above point B.The area of the pipe at point B is and the pipe narrows to an area of at point C.Assume that the water is an ideal fluid in laminar flow.The density of water is 1000 kg/m³.The rate at which the water level is falling in the tank is closest to

A)300 mm/s.
B)340 mm/s.
C)250 mm/s.
D)210 mm/s.
E)160 mm/s.