Answer:
C.
Explanation:
The definition of a fossil is the preserved remains of a prehistoric organism or is slang for someone or something that is outdated. An example of a fossil is the preserved remains from a prehistoric organism that have been preserved inside rock.
Mandatory friction makes it difficult for a free body of mass to move with constant speed.
The _quamtum mechanical_ model of the atom states that an electron's exact location within an atom can not be determined, but its probable location can be estimated within a three-dimensional region called an atomic orbital and that an electron's properties within an orbital can only be described by a set of mathematical values called a quantum number.
The correct answer is The electromagnetic waves appear more in red color.
<span>Since red is at the low-frequency end of the visible spectrum, we say that light from a receding star is shifted toward red, or redshifted.</span>
Answer:
B.
It will be greater than 10 J.
Explanation:
The total mechanical energy of an object is the sum of its potential energy (PE) and its kinetic energy (KE):
E = PE + KE
According to the law of conservation of energy, when there are no frictional forces on an object, its mechanical energy is conserved.
The potential energy PE is the energy due to the position of the object: the highest the object above the ground, the highest its PE.
The kinetic energy KE is the energy due to the motion of the object: the highest its speed, the largest its KE.
Here at the beginning, when it is at the top of the roof, the baseball has:
PE = 120 J
KE = 10 J
So the total energy is
E = 120 + 10 = 130 J
As the ball falls down, its potential energy decreases, since its height decreases; as a result, since the total energy must remain constant, its kinetic energy increases (as its speed increases).
Therefore, when the ball reaches the ground, its kinetic energy must be greater than 10 J.
