Coulomb, unit of electric charge in the metre - kilogram - second - ampere system, the basis of the SI system of physical units. It is abbreviated as C. The coulomb is defined as the quantity of electricity transported in one second by a current of one ampere.
The potential energy is stronger at the start of the bounce and when it is near the end bounce the balls accelerated rate will be lower because the force has decreased . Also I love your profile picture miraculous rocks !