What causes flaming combustion to occur?

select one:
a. a solid fuel mixes with an adequate amount of liquid fuel to be able to sustain an open burning flame.
b. a gaseous fuel mixes with an adequate amount of oxygen and heats to ignition temperature.
c. a solid fuel encounters an open flame and entrains enough air to ignite.
d. a gaseous fuel encounters an external heat source and experiences piloted ignition.

Acommercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at -35°c by rejecting waste heat to cooling water that enters the condenser at 18°c at a rate of 0.25 kg/s and leaves at 26°c. the refrigerant enters the condenser at 1.2 mpa and 50°c. if the compressor consumes 3.3 kw of power, determine (a) the mass flow rate of the refrigerant, (b) the refrigeration load, (c) the cop, and (d) the minimum power input to the compressor for the same refrigeration load.

Which of the following statements comparing electron microscopy and light microscopy is false? which of the following statements comparing electron microscopy and light microscopy is false? both the electron microscope and the light microscope use the same wavelengths for illumination. images produced by light microscopes can be in color, whereas electron microscope images are black and white unless they are artificially colored. the electron microscope has greater resolution than the light microscope. electron microscopes can allow examination of viruses and internal cell structures, whereas light microscopes are limited to objects that are 0.5 micrometers and larger. request answer

You notice the birds sitting on the electrical wires which of the following explain why the birds don't get shocked