The zone that gases always accelerate upward is the Luminous flame zone. The fire plume is the column of hot gases, flames and smoke rising above a fire. Gases accelerate upward toward the always luminous flame zone. The luminous flame height is the distance between the base of a flame and the point at which the plume is luminous half the time and transparent half the time.
Because dark line spectra result from passing white light through ionized gasses and plasmas, which is what the atmosphere of stars are made of. These frequencies are scattered by the star's atmosphere as it leaves the surface (photosphere) of the star, and don't make it to earth.
Answer:
Explanation:
Given
Volume of bucket 
Time taken to fill the bucket 
so volume flow rate is 
1 gal is equivalent to 

mass flow rate 


(b)Average velocity through nozzle exit



Answer:
HELIOS- The god of the sun in
HAZMAT-Hazardous materials
NIRSpec- Near Infrared Spectrograph
Explanation: