Answer:
9.45 kWh
Explanation:
Energy = Power × time
E = 900 W × (1.5 h/day × 7 day)
E = 9450 Wh
E = 9.45 kWh
Answer:
Option A
The cost of keeping the semiconductor below the critical temperature is unreasonable
Explanation:
First of all, we need to understand what superconductors are. Superconductors are special materials that conduct electrical current with almost zero resistance. This means that there is little or no need for a voltage source to be connected to them. As a matter of fact, once a superconductor is connected to a power supply, one can remove the power supply and the current will still flow.
However, most superconducts can only conduct at very low temperatures up to -200 degrees Celcius. This is because, at that temperature, their atoms and molecules are relatively settled, hence they pose little or no resistance to the flow of current.
This as you can guess is extremely difficult to do, as you will need a lot of effort to cool it to that temperature and maintain it.
This makes option a the answer:
The cost of keeping the semiconductor below the critical temperature is unreasonable.
Lamp Wattage is utilized with a CU of 0.75 and 80 percent of the available light reaches the work surface, the remaining 20 percent is absorbed by walls and other objects in the space, resulting in an illumination level of 50 f-c over a 100 ft2 area
The term "lumen" refers to the emission of "luminous flux," which is a measurement of the total amount of visible light emitted by a source in a certain amount of time. The illumination level over a 100 ft2 area will be 50 f-c Lamp Wattage with a CU of 0.75 used, with 80 percent of the available light reaching the work surface and the remaining 20 percent being absorbed by walls and other objects in the room.
Total Lamp Wattage = Number of Lamps X Wattage of Each Lamp.
The fixtures' total wattage is 2 x 32, or 64 watts.
Lumen per Fixtures equals Lumen Efficiency (Lumen per Watt) times the Watt of each Fixture
85x 64 = 5440 lumens per fixture.
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Answer:
Explanation:
Since the formula for kinetic energy of an object is:
Where m is the mass of the object and v is the speed. We can substitute m = 
kg and v = 17900m/s:
When a red giant has insufficient mass it pretty much sheds its outer layer to leave the center core know as the white dwarf
