If there are no windows, then the illumination in the room depends
only on the room and what's in it, not on anything outside.
The time of day has no effect. The other things all do.
<span>D transformed into gravitational potential energy.</span>
Momentum is a vector quantity, and is always conserved. Whenever a collision occurs between two objects, the objects behave under the principle of conservation of momentum. Therefore, if an object moves in the direction opposite to its original direction after a collision, then this indicates that the momentum of the colliding object was greater than the object under consideration.
