Answer:
Distance, d = 99990 meters
Explanation:
It is given that,
Speed of the train, v = 200 km/h = 55.55 m/s
Time taken, t = 1800 s
Let d is the distance covered by the train. We know that the speed of an object is given by total distance covered divided by total time taken. Mathematically, it is given by :



d = 99990 m
So, the distance covered by the train is 99990 meters. Hence, this is the required solution.
The answer is that the reverse arrows pointing to the left needs to release energy. The molecules in the gas state are free such that they can travel from one point to another easily. They have the highest amount of energy. So, if you want the molecules to come closer together, you need to remove the energy to keep them in place. Therefore, the arrows pointing to the right require removal of energy.
Lose its magnetic properties
The difference between the frequencies of the piano key and the tuning fork gives the frequency of the beats.
When the tuning fork is 405 Hz, and no beats are heard, then the piano key is also 405 Hz.
When the piano key is 405 Hz and the tuning fork is 402 Hz, then 405 - 402 = 3 beats are heard.
The piano key is 405 Hz.