Answer:
Explanation:
A solar collector is a device that absords Sun's heat energy to heat air or water. It is majorly used for heating purpose, and do not generate electricity directly.
The flow tubes and collector plate are black in color so as to increase the intensity of heat generated by the collector. A black body is a good absorber of heat, it absorbs most heat directed to the collector. Also, a black body is a good radiator of heat, the heat absorbed is rediated to the appropriate channels for the heating of water or air molecules. The black color increases the efficeincy and percentage of solar energy absorbed by the collector.
If a reflective color is used (e.g white), major percentage of the incident heat would be reflected. This would decrease the efficiency of the solar collector.
Answer:
D
Explanation:
Gamma radiation penetrates the cell wall of prokaryotic organisms such as bacteria and can inhibit their metabolic functions as well as destroy their DNA.
Debunking the other answers:
A is incorrect as Gamma radiation is used in the treatment of cancer via radiotherapy.
B is incorrect as Gamma rays are too small and would just penetrate any smoke particles.
C is incorrect because Gamma rays are used to disinfect food products to prevent food borne illness. Irradiation is safe to use on food and does not make it radioactive.
Thus, D is correct.
For this problem, we use the formula for sensible heat which is written below:
Q= mCpΔT
where Q is the energy
Cp is the specific heat capacity
ΔT is the temperature difference
Q = (55.5 g)(<span>0.214 cal/g</span>·°C)(48.6°C- 23°C)
<em>Q = 304.05 cal</em>
