Answer:
If there is a shaft with headgear, then mining can take place until that depth of the shaft. If it is accessed horizontal Adits, it can mine until the lowest Adit from upwards. If it is accessed decline, the development and mining can continue so long as economic exploitation is possible.
Explanation:
What are the disadvantages of mining headgear? They totally cut off your vision of anything above your head. They are hot, most of the time
Answer:
b. spark plugs
Explanation:
Diesel engines are characterized in that the mechanism that activates the explosion of fuel is high pressures, so when the piston reaches the top of the cylinder, the pressure of the air-diessel mixture is so high that it causes the explosion, this It is what generates the power in a diesel engine.
Answer:
C. Zinc Blende
Explanation:
Out of the three possible crystal structures, only Zinc Blends is the unit cell structures which have four formula. Units per unit cell.
Therefore Zinc Blende is the only possible unit structures of AX ceramic material.
Go through the attached file for further details as to how I came up with the answer.
Answer:

Explanation:
Given that
Angular velocity (ω)= 0.6 rad/s
Angular acceleration (α)= 0.3 
Radius (r)= 0.2 m
We know that is disc is rotating and having angular acceleration then it will have two acceleration .one is radial acceleration and other one is tangential acceleration.
So






So the total acceleration ,a


