Which of the following is MOST likely to be true about a service manager?

#5 Air undergoes an adiabatic compression in a piston-cylinder assembly from P1= 1 atm and Ti=70 oF to P2= 5 atm. Employing idea

otez555 [7]

Answer:

The work transfer per unit mass is approximately 149.89 kJ

The heat transfer for an adiabatic process = 0

Explanation:

The given information are;

P₁ = 1 atm

T₁ = 70°F = 294.2611 F

P₂ = 5 atm

γ = 1.5

Therefore, we have for adiabatic system under compression

$T_{2} = T_{1}\cdot \left (\dfrac{P_{2}}{P_{1}} \right )^{\dfrac{\gamma -1}{\gamma }}$

Therefore, we have;

$T_{2} = 294.2611 \times \left (\dfrac{5}{1} \right )^{\dfrac{1.5 -1}{1.5 }} \approx 503.179 \ K$

The p·dV work is given as follows;

$p \cdot dV = m \cdot c_v \cdot (T_2 - T_1)$

Therefore, we have;

Taking air as a diatomic gas, we have;

$C_v = \dfrac{5\times R}{2} = \dfrac{5\times 8.314}{2} = 20.785 \ J/(mol \cdot K)$

The molar mass of air = 28.97 g/mol

Therefore, we have

$c_v = \dfrac{C_v}{Molar \ mass} = \dfrac{20.785}{28.97} \approx 0.7175 \ kJ/(kg \cdot K)$

The work done per unit mass of gas is therefore;

$p \cdot dV =W = 1 \times 0.7175 \times (503.179 - 294.2611) \approx 149.89 \ kJ$

The work transfer per unit mass ≈ 149.89 kJ

The heat transfer for an adiabatic process = 0.

8 0

3 years ago

The yield strength of mild steel is 150 MPa for an average grain diameter of 0.038 mm ; yield strength is 250 MPa for average gr

djyliett [7]

Answer:

Explanation:

Hall-Petch equation provides direct relations between the strength of the material and the grain size:

σ=σ0+k/√d , where d- grain size, σ- strength for the given gran size, σ0 and k are the equation constants.

As in this problem, we don't know the constants of the equation, but we know two properties of the material, we are able to find them from the system of equations:

σ1=σ0+k/√d1

σ2=σ0+k/√d2 , where 1 and 2 represent 150MPa and 250MPa strength of the steel.

Note, that for the given problem, there is no need to convert units to SI, as constants can have any units, which are convenient for us.

From the system of equations calculations, we can find constant: σ0=55.196 MPa, k=18.48 MPa*mm^(0.5)

Now we are able to calculate strength for the grain diameter of 0.004 mm:

σ=55.196+18.48/(√0.004)=347.39 MPa

The strength of the steel with the grais size of 0.004 mm is 347.39 MPa.

6 0

4 years ago

If my friend have the corona what do I do

nordsb [41]

(E. Call the hospital to take them away

5 0

3 years ago

Read 2 more answers

The lattice constant of a simple cubic primitive cell is 5.28 Å. Determine the distancebetween the nearest parallel ( a ) (100),

skelet666 [1.2K]

Answer:

a)5.28 Å , b)3.73 Å , c)3.048 Å

Explanation:

the atoms are situated only at the corners of cube.Each and every atom in simple cubic primitive at the corner is shared with 8 adjacent unit cells.

Therefore, a particular unit cell consist only 1/8th part of an atom.

The lattice constant of a simple cubic primitive cell is 5.28 Å

We know formula of distance,

d = $\frac{a}{\sqrt{h^{2}+k^{2}+l^{2}}}$

a)(100)

a=5.28 Å

Distance = $\frac{5.28 Å}{\sqrt{1^{2}+0^{2}+0^{2}}}$ =5.28 Å

b)(110)

Distance = $\frac{5.28}{\sqrt{1^{2}+1^{2}+0^{2}}}$ = 3.73 Å

c)(111)

Distance= $\frac{5.28}{\sqrt{1^{2}+1^{2}+1^{2}}}$ = 3.048 Å

6 0

3 years ago

What can your employer do to protect you from overhead power lines?

agasfer [191]

Answer:

Have the power company install insulated sleeves (also known as “eels”) over power lines.

Wearing PPE is the only way to prevent being electrocuted

Explanation:

To prevent electrocution at workplace, employers can ensure that the power company install insulated sleeves (also known as “eels”) over power lines. Additionally, the employees should wear PPEs which are insulators to prevent electrocution.

5 0

3 years ago