Answer:
In a closed system, the total energy is conserved or remains the same as energy transformations take place.
Explanation:
The law of conservation of energy states that energy cannot be created or destroyed but can be transformed from one form to another.
This law of conservation of energy applies only to a closed system. A closed system is a system which does not exchange energy with its surroundings. All forms of energy conversions occurring within a closed system does not result in an increase or decrease of the total energy of the system, rather, energy remains constant. For example, the universe is a closed system in that all forms of energy conversions occurs within it and energy is not exchanged with an external environment. However, the earth is not a closed system as some of the energy it receives from the sun can be radiated out into space. Since it's an open system, its total energy can change.
Answer:
perihelion
Explanation:
The point at which a planet is closest to the sun is called perihelion. The farthest point is called aphelion
Answer:
Explanation:
The gravitational potential energy gets transformed into translational and rotational kinetic energy, so we can write 
. Since 
(the ball rolls without slipping) and for a solid sphere 
, we have:
So our translational speed will be:
