Objects have mechanical energy if they are in motion and have the ability to do work. Mechanical energy is visible kinetic energy. An object possessing mechanical energy displaces the mass of another object. As mass and velocity increase, so does the force of mechanical energy. Heavier and faster objects will have more kinetic energy than lighter and slower ones. Examples of mechanical energy include a wrecking ball hitting a building and large turbines turning because of a blowing wind. Mechanical energy is sometimes referred to as translational energy.
Energy of this type is the movement of positive or negative electrical charges. The release of the charge changes electrical currents in a light bulb, for example, from potential energy into kinetic energy. This type of energy comes from a variety of sources, such as static, electromagnetic fields and natural phenomena such as lightning. Direct current that flows in a single direction, such as what is found in a battery cell, is another type. Current is a transition of electrical charge.
Particles within a substance that are always moving, stretching and rotating have thermal energy, which produces heat. Thermal energy is produced by inelastic collisions, meaning that the objects that collide change shape and sometimes stick together. An auto collision is an example of an inelastic collision. Increasing thermal energy in a substance can turn that substance to liquid. Adding more thermal energy can turn the liquid into gas.
Music, whether played live or on a radio or other source, is a prime example of vibrational or sound energy. Vibrations pass through the air, causing human eardrums to vibrate. The brain interprets the vibrations as sound, but they are, in truth, energy. Cell phones vibrate and move during an incoming call, producing vibrational energy.
Additional forms are rotational, relativistic and orbital energy. Rotational energy is true to its name as it is about energy rotating around an axis. Relativistic energy is the energy of objects operating at very high speed. Einstein's equation E = mc2 describes it perfectly. An object in orbit, such as a planet, has elliptical energy.