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
mr Goodwill [35]
3 years ago
8

Find the shear stress and the thickness of the boundary layer (a) at the center and (b) at the trailing edge of a smooth flat pl

ate 10 ft wide and 2 ft long parallel to the flow, immersed in 60F water (=1.938 slug/ft3, =1.217×10-5ft2/s =2.359×10-5 lbf.s/ft2) flowing at an undisturbed velocity of 3 ft/s. Assume laminar boundary layer over the whole plate. Also (f) find the total friction drag on one side of the plate.
Physics
1 answer:
melomori [17]3 years ago
7 0

Answer:

a) The shear stress is 0.012

b) The shear stress is 0.0082

c) The total friction drag is 0.329 lbf

Explanation:

Given by the problem:

Length y plate = 2 ft

Width y plate = 10 ft

p = density = 1.938 slug/ft³

v = kinematic viscosity = 1.217x10⁻⁵ft²/s

Absolute viscosity = 2.359x10⁻⁵lbfs/ft²

a) The Reynold number is equal to:

Re=\frac{1*3}{1.217x10^{-5} } =246507, laminar

The boundary layer thickness is equal to:

\delta=\frac{4.91*1}{Re^{0.5} }  =\frac{4.91*1}{246507^{0.5} } =0.0098 ft

The shear stress is equal to:

\tau=0.332(\frac{2.359x10^{-5}*3 }{1}  )(246507)^{0.5} =0.012

b) If the railing edge is 2 ft, the Reynold number is:

Re=\frac{2*3}{1.215x10^{-5} } =493015.6,laminar

The boundary layer is equal to:

\delta=\frac{4.91*2}{493015.6^{0.5} } =0.000019ft

The sear stress is equal to:

\tau=0.332(\frac{2.359x10^{-5}*3 }{2}  )(493015.6^{0.5} )=0.0082

c) The drag coefficient is equal to:

C=\frac{1.328}{\sqrt{Re} } =\frac{1.328}{\sqrt{493015.6} } ==0.0019

The friction drag is equal to:

F=Cp\frac{v^{2} }{2} wL=0.0019*1.938*(\frac{3^{2} }{2} )(10*2)=0.329lbf

You might be interested in
17. In which layer does mantle convection occur?
Anarel [89]

Answer:

D. Asthenosphere

Explanation:

The asthenosphere is relatively plastic part of the mantle which underlies the brittle lithosphere. In the asthenosphere, it is generally believed that the rocks are in ductile state and easily moves. It is the site of convection within the earth. In mantle convection, hot and light materials rises and keeps moving into upper crustal levels till they solidify. Here also, cold and denser materials sinks deeper till they turn to melt. This differences in temperature and density sets up a convective cell within the mantle. Several convective cells are in the mantle.

8 0
3 years ago
Which of the following statements about features on the sun is true
pashok25 [27]
D is the answer because of the solar phonominals
7 0
2 years ago
Power windmills turn in response to the force of high-speed drag. For a sphere moving through a fluid, the resistive force, FR i
Crazy boy [7]

Answer:

The answer is 20727w

Explanation:

The formula is below;

P = d r^2 v^3 *efficiency

In the question, it is stated that the registration ignores efficiency so we are going to ignore efficiency in the equation and use it this way;

P = d r^2 * v^3

d =4.3, r = 1.59, v =n 12.4

Therefore, P = 4.3 X 1.59^2  X 12.4^3 = 20727W

3 0
3 years ago
I don’t get science at all my teacher doesn’t explain anything and I was out of school can anyone explain this to me
bekas [8.4K]
2. Groups
3.Ion
4.NonPolar
5.Metallic Bond
6.Make up most of the atom's mass
7.Atomic Number
8.Seven
5 0
3 years ago
A first order reaction, A -> products, has a rate reaction of .00250 Ms-1 when [A] = . 484 M. (a) What is the rate constant,
tamaranim1 [39]

Answer: a)  The rate constant, k, for this reaction is 0.00516s^{-1}

b) No t_{\frac{1}{2}} does not depend on concentration.

Explanation:

Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.

A\rightarrow products

Given: Order with respect to A = 1

Thus rate law is:

a) Rate=k[A]^1

k= rate constant

0.00250=k[0.484]^1

k=0.00516s^{-1}

The rate constant, k, for this reaction is 0.00516s^{-1}

b) Expression for rate law for first order kinetics is given by:

t=\frac{2.303}{k}\log\frac{a}{a-x}

where,

k = rate constant  

t = age of sample

a = let initial amount of the reactant  

a - x = amount left after decay process  

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

t_{\frac{1}{2}}=\frac{2.303}{k}\log\frac{100}{50}

t_{\frac{1}{2}}=\frac{0.69}{k}

Thus t_{\frac{1}{2}} does not depend on concentration.

8 0
3 years ago
Other questions:
  • a defensive tackle picks up the 0.5kg football to a height of 0.8m in 0.25s .... 1.calculate the work done 2.calculate the power
    7·1 answer
  • Calculate the density of Saturn. Show your work. How does it compare with the density of water? Explain how this can be.
    7·1 answer
  • Do sound waves always travel in straight lines explain
    6·1 answer
  • What kind of organisms are able to convert sunlight into usable energy?
    9·2 answers
  • A car initially traveling at 32.4 m/s undergoes a constant negative acceleration of magnitude 1.70 m/s2 after its brakes are app
    11·1 answer
  • Which element below has chemical properties similar to the chemical properties of fluorine.
    6·1 answer
  • Body 1 has a mass m, and its moving in a circle with a radius r at a speed v. It has a centripetal force. F acting on it. If bod
    9·1 answer
  • Five identical quintuplets leave earth when they reach the age of 21, in the year 2121. Each quintuplet goes on a spaceship jour
    5·1 answer
  • A person uses a match to light charcoal in a grill. Which statement describes
    13·1 answer
  • This graph shows the decomposition of hydrogen peroxide as it is exposed to air. Marty claims that the graph shows that the reac
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!