Answer:
So, insulation essentially works by creating a sort of barrier between the hot and the cold object. This barrier helps to reduce heat transfer by either reflecting the thermal radiation or by decreasing thermal conduction and convection from one object to the other.
Explanation:
The machine whose efficiency is 100% is known as perfect machine .This machine is not possible in real life because every machine is affected by the overcoming friction due to which is efficiency become less than hundred percent .
Regions in the milky way where density waves have caused gas clouds to crash into each other are called clumps.Clumps are molecular clouds (interstellar clouds) with higher density,where lots of dust and gs cores resides. These clouds are the beginning of stars.