Answer:External forces acting on an object may include friction, gravity, normal force, drag, tension, or a human force due to pushing or pulling. When in a non-inertial reference frame (see coordinate system, below), fictitious forces, such as centrifugal pseudoforce are appropriate.
Explanation:
<span>The most common method in removing debris and living
organisms is through a series of sedimentation and heat application. The role
of sedimentation is to use gravity in separating drinkable water and visible
debris. While treating water with heat kills the living organisms.</span>