At the top of the hill, the
ball has 100 J of potential energy. Explain what happens
to Mechanical Energy, Kinetic Energy and Potential
Energy as the ball rolls down and reaches the bottom.

According to this law, energy cannot be generated or annihilated; it can only be transformed from one type of energy to another.

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The answer to your question is below

Explanation:

To explain what happens with the ball we must remember the Law of Conservation of Energy.

This law states that the energy can be neither created nor destroyed only converted from one form of energy to another.

Then,

At the top of the hill, the potential energy is maximum and the kinetic energy equals to zero.

When the ball starts to roll down the potential energy will be lower and the kinetic energy will have a low value.

At the middle of the hill, both energies have the same values.

At the end of the hill, the potential energy will be equal to zero and the kinetic energy will be maximum.

in simple terms, the principle states that the buoyancy force on an object is equal to the weight of the fluid displaced by the object, or the density of the fluid multiplied by the submerged volume times the gravitational acceleration, g. this is also known as upthrust.