Kinetic Energy (KE) Defined

Wikipedia defines kinetic energy as:

In physics, the kinetic energy (KE) of an object is the energy that it possesses due to its motion

Britannica explains kinetic energy as:

Kinetic energy is a form of energy that an object or a particle has by reason of its motion. If work, which transfers energy, is done on an object by applying a net force, the object speeds up and thereby gains kinetic energy.


Kinetic energy is a property of a moving object or particle and depends not only on its motion but also on its mass. The kind of motion may be translation (or motion along a path from one place to another), rotation about an axis, vibration or any combination of motions.


Kinetic Energy In Practice

Imagine you have a rubber ball and a sheet of steel suspended in a frame so it can flex a little. If you throw the ball at the sheet of steel the ball bounces off and the sheet flexes. As the ball bounces off the kinetic energy stored in the ball is increased by the kinetic energy of the steel sheet flexing back.

The amount of kinetic energy stored in the ball compared to it mass is relatively high, so we get a nice high bounce. Now consider a steel ball and a rubber mat. This time the ball is so solid there is little or no flex in the material and in simple terms no kinetic energy stored.

This time as the ball hits the rubber and the ball still bounces off but nowhere near as high because less kinetic energy is stored compared to the mass of ball. You can affect the height of the bounce by changing the density of the rubber or using some exotic polymer.

The problem then, is the rubber or polymer wants to return to its original shape so stored energy is still released causing a micro-vibrations of its own. This is why rubbers or polymers don’t work as well with your HiFi equipment, the aftershocks can still be heard interfering or muddying the sound.

Now consider a box filled with sand and we throw the same steel ball into our sand pit. The area of impact absorbs the vibrations but the tremors from the impact site are absorbed by the neighbouring particles. The energy is dissipated rather than stored so there is no bounce and no aftershock as the particles settle.

In fact because the particles are totally independent of one another they constantly re-order and re-align themselves. They’re much better at dissipating vibrations at multiple amplitudes and frequencies, all occuring at the same time.

This is Particle Impact Damping

Instead of sand if we use ultra-heavy particles of tungsten. Energy is dissipated into our particles more efficiently which turns to heat. The heat generated from these impacts has an additional benefit for tungsten, as tungsten warms up it absorbs vibration more efficiently which can be heard in listening tests if you compare warm vs cold.