If a 10.5 joules is required to move 2.72x10^4 kg train a distance of 15km. what is the acceleration of the train

Explanation:

Work

The work done by an external force F when moving an object by a distance X parallel to its direction is

The second Newton's law gives us the net force acting on an object of mass m which is being moved at an acceleration a:

Replacing the last equation into the first equation

And solving for a

There seems to be some kind of mistake in the data provided, we'll use it anyway

It's a very small value as compared to the dimensions of the rest of the problem.

a.   mass number from atomic number