Look at this picture of a ball rolling down a ramp. B
С
At point A the car has more
than at point B. This means there is more
energy at point A then at point B.
As the car moves down the ramp from Point A, the
energy that is starts with is converted into
energy as it moves. The
energy will remain the same because of the

At point A the car has more height than at point B. This means there is more potential energy at point A than at point B.  As the car moves down the ramp from Point A, the potential energy that it starts with is converted into kinetic energy as it moves. The mechanical energy will remain the same because of the principle of conservation of mechanical energy

Explanation:

The Principle of Conservation of Mechanical Energy

In the absence of friction, the total mechanical energy is conserved. That means that

is constant, being U the potential energy and K the kinetic energy

U=mgh

The theory shown above will help us to complete the sentences to come:

At point A the car has more height than at point B. This means there is more potential energy at point A than at point B.  As the car moves down the ramp from Point A, the potential energy that it starts with is converted into kinetic energy as it moves. The mechanical energy will remain the same because of the principle of conservation of mechanical energy

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.