8bf0eb34_PMM_physics__About_friction__Type
[...and something about it] Machines which are noisy, waste energy. Noise is caused by several types of friction. Additionally, sound itself can cause losses. These may occur inside an object by reflections of sound waves or by emitting vibrations into the surrounding atmosphere. [Type] 
sound
s l i d i n g f r i c t i o n
r o l l i n g f r i c t i o n
e l a s t i c d e f o r m a t i o n
p l a s t i c / i n e l a s t i c d e f o r m a t i o n
l i q u i d f r i c t i o n
e l e c t r o m a g n e t i c f r i c t i o n
t i d a l f r i c t i o n
s o u n d
PMM physics. About friction
Type