Answer:
38 kJ
Explanation:
The solution is obtained using the energy balance:
ΔE=E_in-E_out
U_2-U_1=Q_in+W_in-Q_out
U_2=U_1+Q_in+W_in-Q_out
=38 kJ
Answer:
26.7 min
Explanation:
First, we will find the <u>time required to drill each hole</u>:
- N = 300 x 12/0.75
= 1527.7 rev/min
- fr = 1527.7 (0.015) = 22.916 in/min
Formula for <u>distance per hole</u>: 0.5 + A + 1.75
- A = 0.5 (0.75) tan (90-100 / 2) = 0.315 in
- Tm = (0.5 + 0.315 + 1.75) / 22.916 = 0.112 min
Now, we will calculate the <u>time required to draw back the drill form hole</u>:
= 0.112 / 2 = 0.056 min
Time to move between holes = 1.5 / 15 = 0.1 min
For 100 holes, the number of moves between holes = 99
Total time required to drill 100 holes (t):
t = 100 (0.112 + 0.056) + 99 (0.1) = 26.7 min
Answer:
sorry if wrong
Explanation:
One sheave means that you are using a single drum winder. They are the worst! Double drum winders control easier, brake better and are much more efficient. They save time ( two skips or cages) and can be clutched to perform faster shift transport. A single drum is slow, unbalanced and can be a nightmare if it trips out during hoisting. If the brake system is not perfect it can be a real hairy experience. For a runaway single drum, there is no counterbalance effect. It always runs to destruction. With a double drum, the driver still has a chance to control the winder to a certain extent and he has two sets of brakes to rely on. A single sheave could also mean a shaft with a single compartment. No second means of escape unless there are ladders or stairways. Not a very healthy situation.
Those are just a few points. I am sure much more can be said in favor of a double drum winder and two or more sheaves in the headgear. Most of the shafts I have worked at have multiple winders and up to ten compartments. They all have a small single drum service winder for emergencies and moves of personnel during shift times. They are referred to as the Mary - Annes. Apparently, the name originated in the U.K. where an aristocratic mine owner named the first such winder after his mistress.
Answer:
Logging while drilling (LWD) is a technique of conveying well logging tools into the well borehole downhole as part of the bottom hole assembly (BHA). ... In these situations, the LWD measurement ensures that some measurement of the subsurface is captured in the event that wireline operations are not possible
