1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
gregori [183]
3 years ago
10

A student team is to design a human powered submarine for a design competition. The overall length of the prototype submarine is

2.24 m, and its student designers hope that it can travel fully submerged through water at 0.560 m/s. The water is freshwater (a lake) at T = 15°C. The design team builds a one-eighth scale model to test in their university’s wind tunnel. A shield surrounds the drag balance strut so that the aerodynamic drag of the strut itself does not influence the measured drag. The air in the wind tunnel is at 25°C and at one standard atmosphere pressure. At what air speed do they need to run the wind tunnel in order to achieve similarity?
The students from the previous problem measure the aerodynamic drag on their model submarine in the wind tunnel. They are careful to run the wind tunnel at conditions that ensure similarity with the prototype submarine. Their measured drag force is 2.3 N. Estimate the drag force on the prototype submarine at the conditions given in Problem #3
Physics
2 answers:
Allushta [10]3 years ago
6 0

Answer:

a) The speed is 61.42 m/s

b) The drag force is 10.32 N

Explanation:

a) The Reynold´s number for the model and prototype is:

Re_{m} =\frac{p_{m}V_{m}L_{m}   }{u_{m} }

Re_{p} =\frac{p_{p}V_{p}L_{p}   }{u_{p} }

Equaling both Reynold's number:

\frac{p_{p}V_{p}L_{p}   }{u_{p} }=\frac{p_{m}V_{m}L_{m}   }{u_{m} }

Clearing Vm:

V_{m} =\frac{p_{p}V_{p}L_{p} u_{m}   }{u_{p} p_{m} L_{m} }=\frac{999.1*0.56*8*1.849x10^{-5} }{1.138x10^{-3}*1.184*1 } =61.42m/s

b) The drag force is:

\frac{F_{Dm} }{p_{m}V_{m}^{2}L_{m}^{2}     } =\frac{F_{Dp} }{p_{p}V_{p}^{2}L_{p}^{2}     } \\F_{Dp} =\frac{F_{Dp}p_{p}V_{p}^{2}L_{p}^{2} }{p_{m}V_{m}^{2}L_{m}^{2}     } \\F_{Dp}=\frac{2.3*999.1*0.56^{2} *8^{2} }{1.184*61.42^{2}*1^{2}  } =10.32N

aniked [119]3 years ago
5 0

Answer:

1. The air speed at which wind tunnel should be ran in order to achieve similarity = 61.423 m/s

2. The drag force on the prototype submarine at the conditions given above = 10.325 N.

Explanation:

1. Here we have

Density of water at 15 °C = 999.1 kg/m³

Density of air at 25 °C = 1.184 kg/m³

\mu_{Water} at 15 °C = 1.138 × 10⁻³ kg/(m·s)

\mu_{Air} at 25 °C = 1.849 × 10⁻⁵ kg/(m·s)    

The formula is

\frac{V_m\times \rho_m \times L_m}{\mu_m} = \frac{V_p\times \rho_p \times L_p}{\mu_p}

Where:

V_m = Velocity of the model =

\rho_m = Density of the model medium at the medium temperature = 1.184 kg/m³

L_m = Length of the model = 1/8 × L_p = 0.28 m

\mu_m = Dynamic viscosity of model medium at the model medium temperature = 1.849 × 10⁻⁵ kg/(m·s)

V_p = Velocity of the prototype = 0.560 m/s

\rho_p = Density of the prototype medium at the medium temperature = 999.1 kg/m³

L_p = Length of the prototype = 2.24 m

\mu_p = Dynamic viscosity of prototype medium at the prototype medium temperature 1.138 × 10⁻³ kg/(m·s)

Therefore

{V_m}{} = \frac{V_p\times \rho_p \times L_p \times \mu_m}{\mu_p\times \rho_m \times L_m}

{V_m}{} = \frac{0.560\times 999.1  \times 2.24 \times 1.849 \times 10^{-5}}{1.138 \times 10^{-3}\times 1.184 \times 0.28} =  61.423 m/s

The air speed at which wind tunnel should be ran in order to achieve similarity = 61.423 m/s

2. The drag force on the prototype is given by    

F_{D.p} = F_{D.m}(\frac{\rho_p}{\rho_m} )( \frac{V_p}{V_m})^2  ( \frac{L_p}{L_m})^2\\

Where:

F_{D.p} = Drag force of the prototype

F_{D.m} = Drag force of the model

F_{D.p} =2.3(\frac{999.1 }{1.184} )( \frac{0.560 }{61.423 })^2  ( \frac{2.24 }{0.28})^2\\ =   10.325 N

The drag force on the prototype submarine at the conditions given above = 10.325 N.

You might be interested in
Highlight two factors which shows that heat from the sun does reach the earth's surface by convection.
MAXImum [283]

radiation

when the suns radiation fall on the earth and its objects they receive heat energy and hence get heated. Thus the suns heat reaches the earth by. the process of radiation

3 0
2 years ago
What is the sprinters output at 2.0 s, 4.0 s and 6.0 s?
kari74 [83]

A 59 kg sprinter, starting from rest, runs 47 m in 7.0 s at constant acceleration.?  

What is the sprinter's power output at 2.0 s, 4.0 s, and 6.0 s?  

Instantaneous Power is the force times velocity  

P = Fv  

Because the acceleration is constant, the force will be constant as well  

F = ma  

P = mav  

for constant acceleration, the velocity at each time is found using  

v = at  

P = ma(at) = ma²t  

find the acceleration using kinematic equation  

s = ½at²  

a = 2s/t²  

a = 2(47) / 7.0²  

a = 1.918 m/s²  

P(2.0) = 59(1.918²)2.0 = 434.25 W = 0.43 kW  

P(4.0) = 59(1.918²)4.0 = 868.51 W = 0.87 kW  

P(6.0) = 59(1.918²)6.0 = 1302.76 W = 1.3 kW  

I hope this helped.  


5 0
3 years ago
Mateo’s parents are thinking about investing money to help develop a new fusion power plant. Which issue is most important to co
Inessa [10]
The answer is A because fusion has never been controlled in a non explosive manner. 
7 0
3 years ago
Read 2 more answers
(GIVING BRAINLIEST) do what the following image says.
Delicious77 [7]

Answer:

that pink part that circles around is the pancreas

8 0
2 years ago
Read 2 more answers
Two streams merge to form a river. One stream has a width of 8.9 m, depth of 3.8 m, and current speed of 2.3 m/s. The other stre
SpyIntel [72]
<h2>Depth of river is 4.48 m</h2>

Explanation:

Discharge = Area x Velocity

Discharge of river = Discharge of stream 1 + Discharge of stream 2

A_rv_r=A_1v_1+A_2v_2

Area of stream 1 = w₁ x d₁ = 8.9 x 3.8 = 33.82 m²

Area of stream 2 = w₂ x d₂ = 6.5 x 3.9 = 25.35 m²

Velocity of stream 1 = 2.3 m/s

Velocity of stream 2 = 2.6 m/s

Velocity of river = 3 m/s

\texttt{Area of river = }w_r\times d_r=10.7\times d_r

Substituting

             A_rv_r=A_1v_1+A_2v_2\\\\10.7\times d_r\times 3=33.82\times 2.3+25.35\times 2.6\\\\d_r=4.48m

Depth of river = 4.48 m

7 0
3 years ago
Other questions:
  • The amount of dissolved oxygen in water may decrease because of the 
    14·2 answers
  • How many molecules are indicated by writing 2 H2O? <br><br> A.) 2<br> B.) 3<br> C.) 4<br> D.) 1
    15·2 answers
  • For a wire has a circular cross section with a radius of 1.23mm.
    8·1 answer
  • Which special effects technique is being used in television weather reports in which meteorologists stand in front of moving map
    6·2 answers
  • qual charges, one at rest, the other having a velocity of 104 m/s, are released in a uniform magnetic field. Which charge has th
    7·1 answer
  • Stephanie is riding her bicycle to the park. The chemical energy used to pedal the bicycle is transformed into __________.
    12·2 answers
  • Two soccer players kick the same 1-kg ball at the same time in opposite directions. One kicks with a force of 25 N; the other ki
    5·2 answers
  • Write 4,007,500,000 in scientific notation.
    13·1 answer
  • An influence that can deform a flexible abject or change the motion of an object with mass.​
    5·1 answer
  • Two objects are moving in the xy-plane. Object A has a mass of 3.2 kg and has a velocity = (2.3 m/s)i+ (4.2 m/s)j and object B h
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!