An object's speed and velocity are directly related to its kinetic energy. The kinetic energy of an object is defined as the energy it possesses due to its motion or movement. The faster an object moves, the more kinetic energy it has.
Total mechanical energy is the sum of an object's kinetic energy and potential energy. Potential energy is the energy an object has due to its position or how high it is lifted. When an object moves, its potential energy may be converted to kinetic energy, increasing its total mechanical energy.
Therefore, an object's speed and velocity directly affect its kinetic energy, which in turn affects its total mechanical energy. The higher an object's speed and velocity, the greater its kinetic energy and total mechanical energy.