In fact, entropy of an isolated system never decreases (2nd law of thermodynamics), unless some external energy is provided in order to "restore" order in the system and decrease its entropy.
(note that when external energy is added to the system, it is no longer "isolated").
*This is only true if the question is referring to a certain system within the universe. If we are considering the universe itself as the system, then this option is no longer correct, because no external energy can be provided to the universe, and since the universe is an isolated system, its entropy can never decrease. If we are considering the universe itself as the system, none of the options is true.
The total mechanical energy of the notebook is <u><em>19J</em></u>.
Mechanical energy is the sum of potential energy and kinetic energy. It has no kinetic energy, because it's not moving. So its potential energy is all the mechanical energy it has.
Materials that conduct heat and electricity well in the solid state result when metals bond with metals. <span>This type of bonding is called metallic bonding. Metallic bonding is when positive ions (metals) are in a 'sea of negative electrons'. The electrons are delocalised, which means they can move around easily and carry charge, and this enables it to conduct electricity, even in a solid state.</span>
The basic properties of light are: wavelenght, frequency, energy and speed
Explanation:
Two forces slow him down:
Friction between his body and the ground.
Air resistance between his body and the air.
