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:
The resistance “seen” by the 12-Volt battery is 500 ohms . The total resistance is the sum of the resistors R1 and R2. Each resistor will drop a calculable amount of voltage. This voltage is given by Ohm's Law.
Answer:
The answer 30.07J/sec
Explanation:
GIVEN DATA:
temperature of steam = 40 degree celcius
mass flow rate = 63 kg/h
from saturated water tables,
from temperature 40 °, enthalpy of evaporation value is 2406 kj/kg
rate of heat transfer (Q) can be determine by using following relation
putting all value to get Q value
Q = 45 *2406
Q = 108270 kJ/h
Q = 30.07 kJ/sec
