The law of conservation of energy is a law of science that states that energy cannot be created or destroyed, but only changed from one form into another or transferred from one object to another.<span>
</span>
Explanation:
Electromagnetic waves are the waves which are created as the result of the electrical waves which are perpendicular to each other and also perpendicular to the direction of propagation.
Electromagnetic spectrum is range of the frequencies and their respective wavelengths of the various type of the electromagnetic radiation.
In order of the increasing frequency and the photon energy and the decreasing wavelength the spectrum are:
radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays.
The energy of the radio waves photons is the lowest of all the other waves in the electromagnetic spectrum.
Also, 
Where,
h is Plank's constant having value 
Thus, energy is directly proportional to the frequency. The radio waves have the lowest frequency.
Answer:
Part 1) Time of travel equals 61 seconds
Part 2) Maximum speed equals 39.66 m/s.
Explanation:
The final speed of the train when it completes half of it's journey is given by third equation of kinematics as

where
'v' is the final speed
'u' is initial speed
'a' is acceleration of the body
's' is the distance covered
Applying the given values we get

Now the time taken to attain the above velocity can be calculated by the first equation of kinematics as

Since the deceleration is same as acceleration hence the time to stop in the same distance shall be equal to the time taken to accelerate the first half of distance
Thus total time of journey equals
Part b)
the maximum speed is reached at the point when the train ends it's acceleration thus the maximum speed reached by the train equals 
Answer:L=109.16 m
Explanation:
Given
initial temperature 
Final Temperature 
mass flow rate of cold fluid 
Initial Geothermal water temperature 
Let final Temperature be T
mass flow rate of geothermal water 
diameter of inner wall 

specific heat of water 
balancing energy
Heat lost by hot fluid=heat gained by cold Fluid




As heat exchanger is counter flow therefore





heat lost or gain by Fluid is equal to heat transfer in the heat exchanger
(LMTD)




Answer:
Its color
Explanation: I got it right