Answer:
a.)
I.) Open system
II.) Closed system
b.)
The total momentum of the object and earth system stay the same as the object fall toward the earth
The kinetic energy of the object increases as the object falls toward the earth.
Explanation:
a.)
I.) The system containing only the object is an open system because of the influence of external forces and presence of matters. External forces in this scenario means gravitational force acting on the object. And air is the matter that has influence on the object.
II.) The system containing only the object and earth is a closed system. Because in a closed system, there are no external dissipative forces acting on it. Universe is a closed system. And the mechanical energy of a close system is conserved. The mechanical energy will remain constant. In other words, it will not change (become more or less). This is called the Law of Conservation of Mechanical Energy.
b.) The total momentum of the object and earth system stay the same as the object fall toward the earth. Because momentum will always be conserved.
The kinetic energy of the object increases as the object falls toward the earth. When the object was initially at rest, kinetic energy equals zero
