The total amount of energy stored in the particles of an object is called its internal energy. The internal energy of an object is made up of the kinetic energy due to the random motion of the particles and the potential energy due to the interactive forces among the particles.
Answer:

Now when it will reach at point B then its normal force is just equal to ZERO


Explanation:
Since we need to cross both the loops so least speed at the bottom must be

also by energy conservation this is gained by initial potential energy


so we will have

now we have

here we have
R = 7.5 m
so we have


Now when it will reach at point B then its normal force is just equal to ZERO

now when it reach point C then the speed will be
![mgh - mg(2R_c) = \frac{1}{2]mv_c^2](https://tex.z-dn.net/?f=mgh%20-%20mg%282R_c%29%20%3D%20%5Cfrac%7B1%7D%7B2%5Dmv_c%5E2)


now normal force at point C is given as



You need to know everything is made of atoms they are always colliding and they are never still because you'd think that every thing in space is still all the time even if it's not making visibly
I believe yes they do hope this helps