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3 years ago

Guyss I seriously and urgently need help what are the steps to build a headgear ??

2 answers:

7 0

This is all I could find online hope this helps

The first vertical shafts had a rectangular cross section and were lined with wood. The first Headgears were also made of wood, but as shaft depths and skip payloads increased, steel became the material of choice for building a Headgear.

beks73 [17]3 years ago

4 0

Answer:

Design. Modern headframes are built out of steel, concrete or a combination of both. Timber headframes are no longer used in industrialized countries, but are still used in developing nations

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Two previously undeformed rod-shaped specimens of copper are to be plastically deformed by reducing their cross-sectional areas.

mezya [45]

I am not sure I am stuck on this and I have been for 45 min someone please help me and this girl or boy!!

4 0

3 years ago

What is the activation energy (Q) for a vacancy formation if 10 moles of a metal have 2.3 X 10^13 vacancies at 425°C?

Yakvenalex [24]

Answer:

$Activation\ Energy=2.5\times 10^{-19}\ J$

Explanation:

Using the expression shown below as:

$N_v=N\times e^{-\frac {Q_v}{k\times T}$

Where,

$N_v$ is the number of vacancies

N is the number of defective sites

k is Boltzmann's constant = $1.38\times 10^{-23}\ J/K$

${Q_v}$ is the activation energy

T is the temperature

Given that:

$N_v=2.3\times 10^{13}$

N = 10 moles

1 mole = $6.023\times 10^{23}$

So,

N = $10\times 6.023\times 10^{23}=6.023\times 10^{24}$

Temperature = 425°C

The conversion of T( °C) to T(K) is shown below:

T(K) = T( °C) + 273.15

So,

T = (425 + 273.15) K = 698.15 K

T = 698.15 K

Applying the values as:

$2.3\times 10^{13}=6.023\times 10^{24}\times e^{-\frac {Q_v}{1.38\times 10^{-23}\times 698.15}$

$ln[\frac {2.3}{6.023}\times 10^{-11}]=-\frac {Q_v}{1.38\times 10^{-23}\times 698.15}$

$Q_v=2.5\times 10^{-19}\ J$

4 0

3 years ago

In a lab, scientists grew several generations of offspring of a plant using the method shown. What conclusion can you make about

exis [7]

Answer: c) they have low genetic variability among them.

When a plant is grown for several generations of offspring of a plant, then there are some common things which are to be noted which are found similar in the offspring and in the parent of the offspring. The flowers and fruits and the time or season they come in are absolutely the same.

6 0

1 year ago

On what frequency can you expect to monitor air traffic in and around<br> Lincoln Airport?

Phantasy [73]

Answer:

118.5

Explanation:

Hope this helps!

5 0

2 years ago

In the last 5 meters of braking, you lose ___ of your speed.

expeople1 [14]

Answer:

answer is

3/4

Explanation:

In the last 5 meters of braking, you lose 3/4 of your speed.

5 0

2 years ago

Guyss I seriously and urgently need help what are the steps to build a headgear ??​

Guyss I seriously and urgently need help what are the steps to build a headgear ??