Stars form from an accumulation of gas and dust, which collapses due to gravity and starts to form stars. Stars are typically classified by their spectrum in what is known as the Morgan-Keenan or MK system.
The most common metals used for permanent magnets are iron, nickel, cobalt and some alloys of rare earth metals
Answer:
b-energy is not exchanged
Explanation:
An isolated system is a thermodynamic system in which neither energy nor matter is exchanged with the surroundings.
As such the best statement that will fill the box under an isolated system is that energy is not exchanged.
- In an open system, both matter and energy are exchanged with the surrounding.
- A closed system is one in which energy transfer is permissible but matter is not exchanged.
- Energy cannot be created nor destroyed in any system. They are simply transformed.
Answer:
Here, 5% of energy wasted as a heat lost or work done against frictional forces.
Explanation:
No engine has yet made that can convert its all input energy into mechanical energy. Some of the input energy goes in vain in the form of heat and friction.