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
Serga [27]
3 years ago
6

A student engineer is given a summer job to find the drag force on a new unmaned aerial vehicle that travels at a cruising speed

of 320 km/h in air at 15 C. The student decided to build a 1/50 scale model and test it in a water tunnel at the same temperature.
(a) What conditions are required to ensure the similarity of scale model and prototype.
(b) Find the water speed required to model the prototype.
(c) If the drag force on the model is 5 kN, determine the drag force on the prototype

Engineering
1 answer:
yan [13]3 years ago
3 0

Answer:

b. 1232.08 km/hr

c. 1.02 kn

Explanation:

a) For dynamic similar conditions, the non-dimensional terms R/ρ V2 L2 and ρVL/ μ should be same for both prototype and its model. For these non-dimensional terms , R is drag force, V is velocity in m/s, μ is dynamic viscosity, ρ is density and L is length parameter.

See attachment for the remaining.

You might be interested in
A man weighs 145 lb on earth.Part ASpecify his mass in slugs.Express your answer to three significant figures and include the ap
adell [148]

Answer:

<em>a) 4.51 lbf-s^2/ft</em>

<em>b) 65.8 kg</em>

<em>c) 645 N</em>

<em>d) 23.8 lb</em>

<em>e) 65.8 kg</em>

<em></em>

Explanation:

Weight of the man on Earth = 145 lb

a) Mass in slug is...

32.174 pound = 1 slug

145 pound = x slug

x = 145/32.174 = <em>4.51 lbf-s^2/ft</em>

b) Mass in kg is...

2.205 pounds = 1 kg

145 pounds = x kg

x = 145/2.205 = <em>65.8 kg</em>

c) Weight in Newton = mg

where

m is mass in kg

g is acceleration due to gravity on Earth = 9.81 m/s^2

Weight in Newton = 65.8 x 9.81 = <em>645 N</em>

d) If on the moon with acceleration due to gravity of 5.30 ft/s^2,

1 m/s^2 = 3.2808 ft/s^2

x m/s^2 = 5.30 ft/s^2

x = 5.30/3.2808 = 1.6155 m/s^2

weight in Newton = mg = 65.8 x 1.6155 = 106

weight in pounds = 106/4.448 = <em>23.8 lb</em>

e) The mass of the man does not change on the moon. It will therefore have the same value as his mass here on Earth

mass on the moon = <em>65.8 kg</em>

3 0
3 years ago
In the combination of resistors above, consider the 1.50 µΩ and 0.75 µΩ. How can you classify the connection between these two r
Airida [17]

Answer: they are connected in series.

Explanation:

3 0
3 years ago
An Otto cycle engine is analyzed using the air standard method. Given the conditions at state 1, compression ratio (r), and pres
My name is Ann [436]

Answer:

A)  222.58 kJ / kg

B)  0.8897 M^3/ kg

c)  0.7737 m^3/kg

D)  746.542 k

E)  536.017 kj/kg

efficiency = 58% ( approximately )

Explanation:

Given Data :

Gas constant (R) =  0.287 kJ/ kg.K

T1 = 310 k

P1 ( Kpa ) = 100

r = 11.5 ( compression ratio )

rp = 1.95 ( pressure ratio )

A ) specific internal energy at state 1

 = Cv*T1 =  0.718 * 310 = 222.58 kJ / kg

B) Relative specific volume at state 1

= P1*V1 = R*T1 ( ideal gas equation )

V1 = R*T1 / P1 = (0.287* 10^3*310 ) / 100 * 10^3

V1 = 88.97 / 100 = 0.8897 M^3/ kg

C ) relative specific volume at state 2

Applying  r ( compression ratio) = V1 / V2

11.5 = 0.8897 / V2

V2 = 0.8897 / 11.5 = 0.7737 m^3/kg

D) The temperature (k) at state 2

since the process is an Isentropic process we will apply the p-v-t relation

\frac{T1}{T2} = (\frac{V1}{V2}^{n-1}  ) = (\frac{P2}{P1} )^{\frac{n-1}{n} }

hence T2 = 9^{1.4-1} * 310 = 2.4082 * 310 = 746.542 k

e) specific internal energy at state 2

= Cv*T2 = 0.718  * 746.542 = 536.017 kj/kg

efficiency = output /input = 390.3511 / 667.5448 ≈ 58%

attached is a free hand diagram of an Otto cycle is attached below

3 0
3 years ago
A block of ice weighing 20 lb is taken from the freezer where it was stored at -15"F. How many Btu of heat will be required to c
Rus_ich [418]

Answer:

Heat required =7126.58 Btu.

Explanation:

Given that

Mass m=20 lb

We know that

1 lb =0.45 kg

So 20 lb=9 kg

m=9 kg

Ice at -15° F and we have to covert it at 200° F.

First ice will take sensible heat at up to 32 F then it will take latent heat at constant temperature and temperature will remain 32 F.After that it will convert in water and water will take sensible heat and reach at 200 F.

We know that

Specific heat for ice C_p=2.03\ KJ/kg.K

Latent heat for ice H=336 KJ/kg

Specific heat for ice C_p=4.187\ KJ/kg.K

We know that sensible heat given as

Q=mC_p\Delta T

Heat for -15F to 32 F:

Q=mC_p\Delta T

Q=9\times 2.03(32+15) KJ

Q=858.69 KJ

Heat for 32 Fto 200 F:

Q=mC_p\Delta T

Q=9\times 4.187(200-32) KJ

Q=6330.74 KJ

Total heat=858.69 + 336 +6330.74 KJ

Total heat=7525.43 KJ

We know that 1 KJ=0.947 Btu

So   7525.43 KJ=7126.58 Btu

So heat required to covert ice into water is 7126.58 Btu.

8 0
3 years ago
A cylindrical bar of metal having a diameter of 20.9 mm and a length of 205 mm is deformed elastically in tension with a force o
natita [175]

Answer:

a. 1.91 b.  -8.13 mm

Explanation:

Modulus =stress/strain; calculating stress =F/A, hence determine the strain

Poisson's ratio =(change in diameter/diameter)/strain

8 0
3 years ago
Other questions:
  • The spring has a stiffness k=200 N/m and is unstretched when the 25 kg block is at A. Determine the acceleration of the block wh
    6·1 answer
  • A 5 MW gas turbine power plant is reported to have a thermodynamic efficiency of 35%. Assume products of the combustion reaction
    5·1 answer
  • A venturi meter is to be installed in a 63 mm bore section of a piping system to measure the flow rate of water in it. From spac
    15·1 answer
  • Early American rockets used an RC circuit to set the time for the rocket to begin re-entry after launch (true story). Assume the
    5·1 answer
  • Draw the sequence of BSTs that results when you insert the keys E, A, S, Y, Q, U, E, S, T, I, O, N, in that order into an initia
    10·1 answer
  • How long does it take electrons to get from a car battery to the starting motor? Assume the current is 300 A and the electrons t
    10·1 answer
  • 1) Each of the following would be considered company-confidential except
    10·1 answer
  • Pleaseeee help me with this!!
    10·1 answer
  • Estimate the maximum expected thermal conductivity for a Cermet that contains 58 vol% titanium carbide (TiC) particles in a coba
    8·1 answer
  • New ventures that are based on strategic value, such as valuable technology, are attractive while those with low or no strategic
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!