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2 years ago

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A Coca Cola can with diameter 62 mm and wall thickness 300 um has an internal pressure of 100 kPa. Calculate the principal stres

ses at a point on the cylindrical surface of the can far from its ends.

1 answer:

GarryVolchara [31]2 years ago

4 0

Answer:

$\sigma _1=10.33MPa$

$\sigma _2=5.16MPa$

Explanation:

Given that

Diameter(d)=62 mm

Thickness(t)= 300 μm=0.3 mm

Internal pressure(P)=100 KPa

Actually there is no any shear stress so normal stress will become principle stress.This is the case of thin cylinder.The stress in thin cylinder are hoop stress and longitudinal stress .

The hoop stress

$\sigma _h=\dfrac{Pd}{2t}$

Longitudinal stress

$\sigma _l=\dfrac{Pd}{4t}$

Now by putting the values

$\sigma _h=\dfrac{Pd}{2t}$

$\sigma _h=\dfrac{100\times 62}{2\times 0.3}$

$\sigma _h=10.33MPa$

$\sigma _l=5.16MPa$

So the principle stress are

$\sigma _1=10.33MPa$

$\sigma _2=5.16MPa$

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Answer:

$tan \theta = \frac{(176ft/s)^2}{1000 ft 32.2 ft/s^2}= 0.962$

$\theta = tan^{-1} (0.962) = 43.89$

Explanation:

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We have the forces involved on the figure attached.

For this case we know that the weight is given by:

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And for this case the centripetal acceleration would be given by:

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If we analyze the sum of forces on x and y we have:

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And if we solve for the force we got:

$F = ma cos \theta - mg sin \theta = \frac{mv^2}{r} cos \theta - mg sin \theta$

$\sum F_y = m a_y$

$N - W cos \theta = ma sin \theta$

If we solve for the normal force we got:

$N =W cos \theta + ma sin \theta = \frac{mv^2}{r} sin \theta + mg cos \theta$

In order to find the banking angle we use the fact that F =0

$0 = \frac{mv^2}{r} cos \theta - mg sin \theta$

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The velocity on this case is 120 mi/h if we convert this into ft/ s we got:

$120 mi/h * \frac{5280 ft}{1mi} *\frac{1hr}{3600 s}= 176 ft/s$

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$tan \theta = \frac{(176ft/s)^2}{1000 ft 32.2 ft/s^2}= 0.962$

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2 years ago

An electrical utility delivers 6.25E10 kWh of power to its customers in a year. What is the average power required during the ye

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Answer:

The overall Utility delivered to customers in a year 'U' = 6.25 X 10¹⁰Kwh

However, the average power P, required for a year, t = ? Kw

Expressing their relationship, we will have

U = P x t

Given t = 1 year = 24 x 365 hours (assume a year operation is 365 days)

t = 8760 hours

P = $\frac{62500000000}{8760}$

P = 7134.7Kw

Hence, the average power required during the year is 7,135Kw

Now to calculate the energy used by the power plant in a year (in quads)?

Recall, Efficiency, η = Power Output/Power Input (100)

so, we have

η = P₀/P₁, given

0.45 = $\frac{7134.7Kw}{P₁}$

P₁ = 15,855Kw

the total energy E₁ used in a year = 15,855x24x365 = 138.89MJoules

So to convert this to quads, Note;

1 quads of energy = 10¹⁵ Joules

The total energy used is 0.000000139 quads

Now to find the cubic feet of natural gas required to generate this power?

Note: 0.29Kwh of Power generated = 1 cubic feet of natural gas used

Since, the power plant generated = 62500000000Kwh

The cubic feet of natural gas used = $\frac{62500000000}{0.29}$

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2 years ago

In which of the following branches of engineering is the practice not restricted?

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Answer:

a) civil engineering.

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Civil engineering is a professional engineering program that deals with the construction, design, and maintenance of all the natural and man-made environments including dams, buildings, railways, and roads.

Civil engineering is the branch of engineering that is the practice not restricted because civil engineer is not restricted to academic profession but practice in designing and construction can make someone a professional civil engineer.

Hence, the correct answer is "a)."

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Answer:

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// It takes a parameter of integer called numCycles

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// if numCycles is less than 1, it display "Too few"

if (numCycles < 1){

System.out.println("Too few.");

}

// else if numCycles is less than 1, it display "Too many"

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}

// else it uses for loop to print the number of times to display

// Lather and rinse

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System.out.println(i + ": Lather and rinse.");

}

System.out.println("Done");

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}

Explanation:

The code snippet is written in Java. The method is declared static so that it can be called from another static method. It has a return type of void. It takes an integer as parameter.

It display "Too few" if the passed integer is less than 1. Or it display "Too much" if the passed integer is more than 4. Else it uses for loop to display "Lather and rinse" based on the passed integer.

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2 years ago

. A piston-cylinder device whose piston is resting on top of a set of stops initially contains 0.5 kg of helium gas at 100 kPa a

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Answer:

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8 0

2 years ago