Answer:
η = 40 %
Explanation:
Given that
Qa ,Heat addition= 1000 J
Qr,Heat rejection= 600 J
Work done ,W= 400 J
We know that ,efficiency of a engine given as
Now by putting the values in the above equation ,then we get
η = 0.4
The efficiency in percentage is given as
η = 0.4 x 100 %
η = 40 %
Therefore the answer will be 40%.
Answer:
The blue light has the highest energy.
Explanation:
Body that is hot enough emits light as consequence of its temperature. For example, an iron bar in contact with fire will start to change colors as the temperature increases until it gets to a blue color. That its know as Wien's displacement law, which establishes that the peak of emission for the spectrum will be displaced to shorter wavelengths as the temperature increases.
The same scenario described above can be found in the star, a star with higher temperature will have a blue color and one with lower temperature will have a red color.
(1)
The energy of each wavelength can be determined by means of the following equation:
(2)
but , therefore:
(3)
Where h is the planck's constant and is the frequency.
Notice that it is necessary to express the frequency in units of meters for a better representation of the energy.
⇒
⇒
Case for the bluest light:
Case for the reddest light:
Equation 3 show that if the wavelength is lower the energy will be greater (inversely proportional).
Hence, according with the result and what was explained above, the blue light has the highest energy.