Answer:
Explanation:
Given that,
Efficiency of heat engine,
Temperature of hot source,
We need to find the temperature of cold sink i.e. . The efficiency of heat engine is given by :
So, the temperature of the cold sink is 256.2°C. Hence, this is the required solution.
Answer:
It took 1.28 seconds to his voice to reach the Earth via radio waves.
Explanation:
The electromagnetic spectrum is the distribution of radiation due to the different frequencies at which it radiates and its different intensities, that radiation is formed by electromagnetic waves, which are transverse waves formed by an electric field and a magnetic field perpendicular to it.
The distribution of the radiation in the electromagnetic spectrum can also be given in wavelengths, but it is more frequent to work with it at frequencies, the highest being that of gamma rays, followed by X-rays, ultraviolet rays and the visible region , and those of lower frequencies, which correspond to infrared, microwave and radio waves.
Light propagates as electromagnetic wave in vacuum with a speed of . Therefore, radio waves will have in vacuum the same speed.
Then, to know the time that it took for its voice, the next equation can be used:
(1)
Where c is the speed of light, d is the distance and t is the time.
Notice that t can be isolated from equation 1.
(2)
Hence, it took 1.28 seconds to his voice to reach the Earth via radio waves.
a)If it takes the bird 18.0 minutes to fly 6 km away from the earth, the wind's speed will be 4 m/s.
b) The bird would need 7 minutes and 42 seconds to fly back 6 kilometers if he turned around and flew with the wind.
c)Compared to the 133.33 seconds it would take without the wind, the overall round-trip time is affected by the wind.
<h3>What is velocity?</h3>The change of distance with respect to time is defined as speed. Speed is a scalar quantity. It is a time-based component. Its unit is m/sec.
The given data in the problem is
A seagull flies at a velocity,
The time the bird takes,t=18.0 min
The distance traveled relative to the earth = 6.00 km
a)
The seagull's relative velocity with reference to the ground as;
Air velocity with reference to the ground is;
b)
If the bird turns around and flies with the wind, The time will he take to return 6.00 km is;
The time the bird takes;
c)\
The total round-trip time compared to what it would be with no wind. is;
The time for the round trip is;
Hence the wind's speed, the time bird would need to fly back the total round-trip time will be 4 m/s, 7 minutes and 42 seconds and 1333.33 sec.
To learn more about the velocity, refer to the link: brainly.com/question/862972.
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