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:
Q' = 8 KW.h
Q'=28800 KJ
Explanation:
Given that
Heat Q= 4 KW
time ,t = 2 hours
The amount of energy used in KWh given as
Q ' = Q x t
Q' = 4 x 2 KW.h
Q' = 8 KW.h
We know that
1 h = 60 min = 60 x 60 s = 3600 s
We know that W = 1 J/s
The amount of energy used in KJ given as
Q' = 8 x 3600 = 28800 KJ
Therefore
Q' = 8 KW.h
Q'=28800 KJ
Given Information:
Output power required = Pout = 2.80 MW
Efficiency = η = 30%
Intensity = I = 1180 W/m²
Required Information:
Effective area = A = ?
Answer:
Effective area = A = 7.907x10³ m²
Step-by-step explanation:
A community plans to build a facility to convert solar power into electrical power and this facility has an efficiency of 30%
As we know efficiency is given by
η = Pout/Pin
Where Pout is the output power and Pin is the input power.
Pin = Pout/η
Pin = 2.80x10⁶/0.30
Pin = 9.33x10⁶ W
The effective area of a perfectly absorbing surface used in such an installation can be found using
A = Pin/I
Where I is the in Intensity of the sunlight in W/m²
A = 9.33x10⁶/1180
A = 7.907x10³ m²
Therefore, the effective area of the absorbing surface would be 7.907x10³ m².
Answer:
Explanation:
To measure the current through a resistor, the Ammeter must be placed in series with the resistor so that the same current that passes through the resistor also passes through the Ammeter. Ammeter is a measuring device used to measure current.
If there is a random child, you should ask where they should be and where their parents went. if it your child, they prolly want food or sum.
