Which of the following statements are true? (mark all that apply)
1 answer:
Answer:
(a) and (b)
Explanation:
Energy is the capacity to do work, and exists in various forms. These forms can be converted one to another by the use of appropriate means. Some examples are sound, mechanical, solar, light, which causes the sensation of vision, etc. energy is measured in Joules (J).
The rate of transfer of energy is called power.
i.e Power =
It is measured in Watts (W).
When a white light is disperses into its colors, gray and black are not part of the colors. And a black sometimes could be as a result of the absorption of all other colors of light.
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Since,
Speed = Frequency * WaveLength
=> WaveLength = Speed / Frequency --- (A)
Frequency = 13.0 kHz.
As the radio waves are electromagnetic waves, their speed is equals to the speed of light. Therefore,
Speed = C =
Plug in the values in equation(A):
A => WaveLength =
Ans: Wavelength = 23.077 kilometers.
-i
Speed = Frequency * WaveLength
=> WaveLength = Speed / Frequency --- (A)
Frequency = 13.0 kHz.
As the radio waves are electromagnetic waves, their speed is equals to the speed of light. Therefore,
Speed = C =
Plug in the values in equation(A):
A => WaveLength =
Ans: Wavelength = 23.077 kilometers.
-i
Answer:
Explanation:
Dear Student, this question is incomplete, and to attempt this question, we have attached the complete copy of the question in the image below. Please, Kindly refer to it when going through the solution to the question.
To objective is to find the:
(i) required heat exchanger area.
(ii) flow rate to be maintained in the evaporator.
Given that:
water temperature = 300 K
At a reasonable depth, the water is cold and its temperature = 280 K
The power output W = 2 MW
Efficiency = 3%
where;
However, from the evaporator, the heat transfer Q can be determined by using the formula:
Q = UA(L MTD)
where;
Also;
LMTD = 4.97
Thus, the required heat exchanger area A is calculated by using the formula:
where;
U = overall heat coefficient given as 1200 W/m².K
The mass flow rate:
