Question 1

As shown in the figure, water $\text { (density } 1000 \mathrm {~kg} / \mathrm { m } ^ { 3 } \text { ) }$ is flowing in a pipeline. At point 1 the water speed is  5.90 m/s. Point 2 is 5.20 m above point 1. The cross-sectional area of the pipe is $0.0800 \mathrm {~m} ^ { 2 }$ at point 1 and $0.0200 \mathrm {~m} ^ { 2 }$ at point 2. What is the pressure difference  p 1-p 2  between points 1 and 2? Treat the water as an ideal incompressible fluid.

Accepted Answer

The answer of As shown in the figure, water \(\text...

Question 2

A $1.00 - \mathrm { m } ^ { 3 }$ object floats in water with  20.0%  of its volume above the waterline. What does the object weigh out of the water? The density of water is $1000 \mathrm {~kg} / \mathrm { m } ^ { 3 }$

Accepted Answer

A)   11,800 N 
B)   7,840 N 
C)   9,800 N 
D)   1,960 N

Question 3

A 200-kg flat-bottomed boat floats in fresh water, which has a density of $1000 \mathrm {~kg} / \mathrm { m } ^ { 3 }$
If the base of the boat is  1.42 m wide and  4.53 m long, to what depth is the bottom of the boat submerged when it carries three passengers whose total mass is  257 kg?

Accepted Answer

A)   8.52 cm 
B)   7.95 cm 
C)   7.10 cm 
D)   7.53 cm

Question 4

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.

Accepted Answer

A)   6.0 cm/s 
B)   50 cm/s 
C)   22 cm/s 
D)   51 cm/s

Question 5

What buoyant force does a  0.60-kg solid gold crown experience when it is immersed in water? The density of gold is $19.3 \times 10 ^ { 3 } \mathrm {~kg} / \mathrm { m } ^ { 3 }$ and that of water is $1000 \mathrm {~kg} / \mathrm { m } ^ { 3 }$

Accepted Answer

A)  $3.0 \times 10 ^ { - 4 } \mathrm {~N}$ 
B)  $3.0 \times 10 ^ { - 5 } \mathrm {~N}$ 
C)   0.30 N 
D)  $3.0 \times 10 ^ { - 2 } \mathrm {~N}$

Question 6

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  32m/s, what is its speed in this smaller section if the water behaves like an ideal incompressible fluid?

Accepted Answer

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

Question 7

One of the dangers of tornados and hurricanes is the rapid drop in air pressure that is associated with such storms. Assume that the air pressure inside of a sealed house is  1.02  atm when a hurricane hits. The hurricane rapidly decreases the external air pressure to  0.910  atm. What net outward force is exerted on a square window of the house that is  2.03 m on each side?  (1.00 atm=  $\left. 1.01 \times 10 ^ { 5 } \mathrm {~Pa} \right)$

Accepted Answer

A)  $5.19 \times 10 ^ { 4 } \mathrm {~N}$ 
B)  $5.42 \times 10 ^ { 5 } \mathrm {~N}$ 
C)  $4.82 \times 10 ^ { 5 } \mathrm {~N}$ 
D)  $4.59 \times 10 ^ { 4 } \mathrm {~N}$

Question 8

A person weighing  900 N  is standing on snowshoes. Each snowshoe has area $2500 \mathrm {~cm} ^ { 2 }$ and has

Accepted Answer

A)  $3600 \mathrm {~N} / \mathrm { m } ^ { 2 }$ 
B)  $0.18 \mathrm {~N} / \mathrm { m } ^ { 2 }$ 
C)  $1800 \mathrm {~N} / \mathrm { m } ^ { 2 }$ 
D)  $0.36 \mathrm {~N} / \mathrm { m } ^ { 2 }$

Question 9

How many grams of ethanol $\left( \text { density } 0.80 \mathrm {~g} / \mathrm { cm } ^ { 3 } \right)$ should be added to 5.0 g of chloroform (density $\left. 1.5 \mathrm {~g} / \mathrm { cm } ^ { 3 } \right)$ if the resulting mixture is to have a density of $1.2 \mathrm {~g} / \mathrm { cm } ^ { 3 } ?$ Assume that the fluids do not  change their volumes when they are mixed.

Accepted Answer

A)  1.8 g 
B)  1.6 g 
C)  2.4 g 
D)  2.0 g 
E)  4.4 g

Question 10

The deepest point of the Pacific Ocean is  11,033 m, in the Mariana Trench. What is the gauge pressure in the water at that point? The density of seawater is $1025 \mathrm {~kg} / \mathrm { m } ^ { 3 }$

Accepted Answer

A)  $2.22 \times 10 ^ { 8 } \mathrm {~Pa}$ 
B)  $5.55 \times 10 ^ { 7 } \mathrm {~Pa}$ 
C)  $8.88 \times 10 ^ { 7 } \mathrm {~Pa}$ 
D)  $3.33 \times 10 ^ { 8 } \mathrm {~Pa}$ 
E)  $1.11 \times 10 ^ { 8 } \mathrm {~Pa}$

Question 11

The Aswan High Dam on the Nile River in Egypt is  111 m high. What is the gauge pressure in the water at the foot of the dam? The density of water is $1000 \mathrm {~kg} / \mathrm { m } ^ { 3 }$

Accepted Answer

A)  $1.09 \times 10 ^ { 6 } \mathrm {~Pa}$ 
B)  $1.09 \times 10 ^ { 3 } \mathrm {~Pa}$ 
C)  $1.11 \times 10 ^ { 2 } \mathrm {~Pa}$ 
D)  $1.16 \times 10 ^ { 6 } \mathrm {~Pa}$ 
E)  $1.11 \times 10 ^ { 5 } \mathrm {~Pa}$

Question 12

A container has a vertical tube, whose inner radius is  24.00 mm, connected to it at its side, as shown in the figure. An unknown liquid reaches level A in the container and level B in the tube -level A being  5.0 cm higher than level B. The liquid supports a  20-cm high column of oil, between levels  B  and  C , whose density is $570 \mathrm {~kg} / \mathrm { m } ^ { 3 }$
The mass of the oil is closest to

Accepted Answer

A)  820 
B)  210 
C)  620 
D)  1000 
E)  410

Question 13

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  $Q = \frac { \Delta V } { \Delta t }$  what is the flow rate in pipe  A  ?

Accepted Answer

A)  $Q \sqrt { 2 }$ 
B)   16Q 
C)   4Q 
D)   8Q 
E)   2Q

Question 14

A $50 - \mathrm { cm } ^ { 3 }$ block of wood is floating on water, and a $50 - \mathrm { cm } ^ { 3 }$ chunk of iron is totally submerged in the water. Which one has the greater buoyant force on it?

Accepted Answer

A)  the wood 
B)  Both have the same buoyant force. 
C)  the iron 
D)  It cannot be determined without knowing their densities.

Question 15

A polar bear of mass  200 kg stands on an ice floe that is a uniform  1.0 m thick. What is the minimum area of the floe that will just support the bear in saltwater of density $1030 \mathrm {~kg} / \mathrm { m } ^ { 3 } ?$ The density of ice is $980 \mathrm {~kg} / \mathrm { m } ^ { 3 }$

Accepted Answer

A)  $2.0 \mathrm {~m} ^ { 2 }$ 
B)  $4.0 \mathrm {~m} ^ { 2 }$ 
C)  $3.0 \mathrm {~m} ^ { 2 }$ 
D)  $1.0 \mathrm {~m} ^ { 2 }$

Question 16

A hollow steel ball of diameter  3.0 m just barely floats in water. What is the wall thickness of the ball? $\left( \rho \mathrm { Fe } = 7.87 \mathrm {~g} / \mathrm { cm } ^ { 3 } , \rho _ { \text {water } } = 1.00 \mathrm {~g} / \mathrm { cm } ^ { 3 } \right)$

Accepted Answer

A)   6.6 cm 
B)   131 cm 
C)   37 cm 
D)   79 cm

Question 17

A container consists of two vertical cylindrical columns of different diameter connected by a narrow horizontal section, as shown in the figure. The open faces of the two columns are closed by very light plates that can move up and down without friction. The tube diameter at  A  is  35.0 cm and at  B  it is  10.2 cm. This container is filled with oil of density $0.820 \mathrm {~g} / \mathrm { cm } ^ { 3 }$ If a 125-kg object is placed on the larger plate at  A , how much mass should be placed on the smaller plate at  B  to balance it?.

Accepted Answer

The answer of A container consists of two vertical cylindrical...

Question 18

A styrofoam sphere of radius  R  has a density $\rho .$ You now carefully compress the sphere so its radius is  R/2 . What is the density of the compressed sphere?

Accepted Answer

A)  $8 \rho$ 
B)  $4 \rho$ 
C)  $\rho \sqrt { 2 }$ 
D)  $\rho \sqrt { 8 }$ 
E)  $2 \rho$

Exam 10: Fluids

A 1.00−m31.00 - \mathrm { m } ^ { 3 }1.00−m3 object floats in water with 20.0% of its volume above the waterline. What does the object weigh out of the water? The density of water is 1000 kg/m31000 \mathrm {~kg} / \mathrm { m } ^ { 3 }1000 kg/m3

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.

What buoyant force does a 0.60-kg solid gold crown experience when it is immersed in water? The density of gold is 19.3×103 kg/m319.3 \times 10 ^ { 3 } \mathrm {~kg} / \mathrm { m } ^ { 3 }19.3×103 kg/m3 and that of water is 1000 kg/m31000 \mathrm {~kg} / \mathrm { m } ^ { 3 }1000 kg/m3

A person weighing 900 N is standing on snowshoes. Each snowshoe has area 2500 cm22500 \mathrm {~cm} ^ { 2 }2500 cm2 and has

The deepest point of the Pacific Ocean is 11,033 m, in the Mariana Trench. What is the gauge pressure in the water at that point? The density of seawater is 1025 kg/m31025 \mathrm {~kg} / \mathrm { m } ^ { 3 }1025 kg/m3

The Aswan High Dam on the Nile River in Egypt is 111 m high. What is the gauge pressure in the water at the foot of the dam? The density of water is 1000 kg/m31000 \mathrm {~kg} / \mathrm { m } ^ { 3 }1000 kg/m3

A 50−cm350 - \mathrm { cm } ^ { 3 }50−cm3 block of wood is floating on water, and a 50−cm350 - \mathrm { cm } ^ { 3 }50−cm3 chunk of iron is totally submerged in the water. Which one has the greater buoyant force on it?

A styrofoam sphere of radius R has a density ρ.\rho .ρ. You now carefully compress the sphere so its radius is R/2 . What is the density of the compressed sphere?

A $1.00 - \mathrm { m } ^ { 3 }$ object floats in water with 20.0% of its volume above the waterline. What does the object weigh out of the water? The density of water is $1000 \mathrm {~kg} / \mathrm { m } ^ { 3 }$

What buoyant force does a 0.60-kg solid gold crown experience when it is immersed in water? The density of gold is $19.3 \times 10 ^ { 3 } \mathrm {~kg} / \mathrm { m } ^ { 3 }$ and that of water is $1000 \mathrm {~kg} / \mathrm { m } ^ { 3 }$

A person weighing 900 N is standing on snowshoes. Each snowshoe has area $2500 \mathrm {~cm} ^ { 2 }$ and has

The deepest point of the Pacific Ocean is 11,033 m, in the Mariana Trench. What is the gauge pressure in the water at that point? The density of seawater is $1025 \mathrm {~kg} / \mathrm { m } ^ { 3 }$

The Aswan High Dam on the Nile River in Egypt is 111 m high. What is the gauge pressure in the water at the foot of the dam? The density of water is $1000 \mathrm {~kg} / \mathrm { m } ^ { 3 }$

A $50 - \mathrm { cm } ^ { 3 }$ block of wood is floating on water, and a $50 - \mathrm { cm } ^ { 3 }$ chunk of iron is totally submerged in the water. Which one has the greater buoyant force on it?

A styrofoam sphere of radius R has a density $\rho .$ You now carefully compress the sphere so its radius is R/2 . What is the density of the compressed sphere?