Power is the rate work is usually done in.
Answer:

Explanation:
As we know that train is initially moving with the speed

now we know that

now the final speed of the train when it crossed the crossing


now we can use kinematics here



Now the time to cross that junction is given as



The Sun's magnetic field goes through a cycle, called the solar cycle. Every 11 years or so, the Sun's magnetic field completely flips. This means that the Sun's north and south poles switch places. Then it takes about another 11 years for the Sun's north and south poles to flip back again.