A. Bones provide protection for organs in the body
<span>When the Sun’s energy moves through space, it reaches Earth’s atmosphere and finally the surface. This radiant solar energy warms the atmosphere and becomes heat energy. This heat energy is transferred throughout the planet’s systems in three ways: by radiation, conduction, and convection</span>
Answer:
The value is 
Explanation:
From the question we are told that
The initial speed of the roller coaster is 
The length of the hill is 
The acceleration of the roller coaster is 
Generally the acceleration is mathematically represented as
Here 
is the initial time which is equal to zero
is the final velocity which is mathematically represented as
So
Solving this using quadratic formula we obtain
Generally time cannot be negative so
Generally the final velocity is mathematically represented as
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.
