Answer:
It looks like A is the correct answer.
Physics – branch of science that studies matter and its motion through space and time, along with related concepts such as energy and force. Physics is one of the "fundamental sciences" because the other natural sciences (like biology, geology etc.) deal with systems that seem to obey the laws of physics.
Answer:
The value is
Explanation:
From the question we are that
The velocity 
The time taken is
The total mass of the train is 
Generally the average power delivered is mathematically represented as
=>
=>
Answer:
maybe alternator..generator..
Answer: D. Infrared
Infrared is the best way to observe it.