Answers:
a) 5400000 J
b) 45.92 m
Explanation:
a) The kinetic energy 
of an object is given by:
Where:
is the mass of the train
is the speed of the train
Solving the equation:
This is the train's kinetic energy at its top speed
b) Now, according to the Conservation of Energy Law, the total initial energy is equal to the total final energy:
Where:
is the train's initial kinetic energy
is the train's initial potential energy
is the train's final kinetic energy
is the train's final potential energy, where 
is the acceleration due gravity and 
is the height.
Rewriting the equation with the given values:
Finding :
The frequency of the
scattered photon decreases or it will be lower compare to the frequency of
incident photon. An x-ray photon scatters in one direction after a collision
and some energy is transferred to the electron as it recoils in another
direction resulting to have less energy in the scattered photon. In addition, the
frequencies will also depend on the differences of the angle at which the
scattered photon leaves the collision and this incident is called Compton Effect.
-- If the field were inclined to the surface, then it would have
some component parallel to the surface.
-- Then, since we're talking about a conductor, the charges
on the object would move in response to that component
of the field, until there was no longer any component of the
field trying to move them.
Boyle's law states that when you "shrink"(change its size) a container the pressure increases so the best answer would be D-volume is decreased.
<span>by placing dams in tidal areas. ITS the only one that has anything to do with water</span>
