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3 years ago

Ignore swell and shrinkage for this problem.

Engineering

1 answer:

Komok [63]3 years ago

6 0

Answer:

(a) 5.3

(b) 6

Explanation:

First we calculate time required for excavator to fill 1 truck:

Time to Fill 1 Truck = (No. of Cycles To Fill)(Cycle Time)

Time to Fill 1 Truck = (3)(33 sec)

Time to Fill 1 Truck = 99 sec

Now, we find the time taken by a truck to come back to excavator, after dumping:

Time of Return = Hauling Time + Time to Dump + Time to Come Back

Time of Return = 5 min + 45 sec + 3 min

Time of Return = 300 sec + 45 sec + 180 sec

Time of Return = 525 sec

(a)

In order to balance the output of excavator with number of trucks, following condition must be satisfied:

Time of Return = (No. of Trucks)(Time to Fill 1 Truck)

525 sec = (No. of Trucks)(99 sec)

No. of Trucks = 525 sec/99 sec

No. of Trucks = 5.3

(b)

If we round up the number of trucks, we get:

No. of Trucks = 6

(c)

If we round down the number of trucks, we get:

No. of Trucks = 5

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A silicon carbide plate fractured in bending when a blunt load was applied to the plate center. The distance between the fractur

Amanda [17]

Question in order:

A silicon carbide plate fractures in bending when a blunt load was applied to the plate center. The distance between the fracture origin and the mirror/mist boundary on the fracture surface was 0.796 mm. To determine the stress used to break the plate, three samples of the same material were tested and produced the following. What is the estimate of the stress present at the time of fracture for the original plate?

Mirror Radius (mm) Bending Failure Stress (MPa)

0.603 225

0.203 368

0.162 442

Answer:

191 MPa

Explanation:

Failure stress of bending is Inversely proportional to the mirror radius

$Bending Stress = \frac{1}{(Mirror Radius)^{n}}$

At mirror radius 1 = 0.603 mm Bending stress 1 = 225 Mpa..............(1)

At mirror radius 2 = 0.203 mm Bending stress 2 = 368 Mpa...............(2)

At mirror radius 3 = 0.162 mm Bending stress 3 = 442 Mpa...............(3)

comparing case 1 and 2 using the above equation

$\frac{Stress 1}{Stress 2} = ({\frac{Radius 2}{Radius 1}})^{n_1}$

$\frac{225}{368} = ({\frac{0.203}{0.603}})^{n_1}$

$0.6114 = (0.3366)^{n_1}$

Taking the natural logarithm of both side

ln(0.6114) = n ln(0.3366)

n₁ = ln(0.6114)/ln(0.3366)

n₁ = 0.452

comparing case 2 and 3 using the above equation

$\frac{Stress 2}{Stress 3} = ({\frac{Radius 3}{Radius 2}})^{n_2}$

$\frac{368}{442} = ({\frac{0.162}{0.203}})^{n_2}$

$0.8326 = (0.7980)^{n_2}$

Taking the natural logarithm of both side

ln(0.8326) = n ln(0.7980)

n₂ = ln(0.8326)/ln(0.7980)

n₂ = 0.821

comparing case 1 and 3 using the above equation

$\frac{Stress 1}{Stress 3} = ({\frac{Radius 3}{Radius 1}})^{n_3}$

$\frac{225}{442} = ({\frac{0.162}{0.603}})^{n_3}$

$0.5090 = (0.2687)^{n_3}$

Taking the natural logarithm of both side

ln(0.5090) = n ln(0.2687)

n₃ = ln(0.5090)/ln(0.2687)

n₃ = 0.514

average for n

$n = \frac{n_1 + n_2 + n_3}{3}$

$n = \frac{0.452 +0.821 + 0.514}{3}$

n = 0.596

Hence to get bending stress x at mirror radius 0.796

$\frac{Stress x}{Stress 3} = ({\frac{Radius 3}{Radius x}})^{0.596}$

$\frac{Stress x}{225} = ({\frac{0.603}{0.796}})^{0.596}$

$\frac{Stress x}{225} = 0.8475$

stress x = 191 MPa

3 0

3 years ago

Write the output expression for a NOR gate with inputs , , and .

mezya [45]

Answer:

Logic NOR Gate Equivalent

The Boolean expression for a logic NOR gate is denoted by a plus sign, ( + ) with a line or Overline, ( ‾‾ ) over the expression to signify the NOT or logical negation of the NOR gate giving us the Boolean expression of: A+B = Q.

4 0

2 years ago

What fuel do rockets use

natta225 [31]

Liquid Hydrogen is the fuel used by rockets.

Explanation:

Liquid hydrogen which can be chemically denoted as " $LH_{2}$ " is often considered as the significant fuels for rocket.

However rocket in its lower stages uses fuels such as Kerosene and oxygen where as in the higher stages such as second and third stages it uses liquid hydrogen.

Liquid hydrogen is known to easily cool the nozzle and then also other parts of the rocket before mixing with the oxidizer such as the oxygen.

Thus liquid hydrogen helps in preventing nozzle erosion and also reduces combustion chamber.
Liquid hydrogen one the other hand is very expensive as 384,071 gallons of it will cost approximately $376,389.58 .

Thus liquid hydrogen is effectively used as a fuel for rocket.

8 0

3 years ago

Read 2 more answers

For methyl chloride at 100°C the second and third virial coefficients are: B = −242.5 cm 3 ·mol −1 C = 25,200 cm 6 ·mol −2 Calcu

bogdanovich [222]

Answer:

a)W=12.62 kJ/mol

b)W=12.59 kJ/mol

Explanation:

At T = 100 °C the second and third virial coefficients are

B = -242.5 cm^3 mol^-1