Given, elapsed time in gravity filter = 1 sec

To calculate the height of fall in a single descent, we can use the following formula:

h = 1/2 * g * t^2

where,
h = height of fall
g = acceleration due to gravity = 9.8 m/s^2
t = elapsed time = 1 sec

Substituting the given values in the above equation, we get:

h = 1/2 * 9.8 * 1^2
h = 4.9 m

Therefore, the height of fall in a single descent is 4.9 m.

Explanation:
Gravity filters are used in water treatment plants to remove suspended particles from water. These filters work on the principle of gravity, where water is allowed to flow through a porous medium under the influence of gravity. The suspended particles get trapped in the medium, and the filtered water is collected at the bottom.

In a gravity filter, the height of fall refers to the distance that the water falls from the top of the filter to the surface of the filter medium. This height is an important parameter that affects the filtration rate and efficiency of the filter.

The formula used to calculate the height of fall is derived from the equation of motion, where the distance traveled by an object under constant acceleration is given by d = 1/2 * a * t^2. In the case of a gravity filter, the acceleration is equal to the acceleration due to gravity, which is 9.8 m/s^2.

By substituting the given values in the formula, we can calculate the height of fall in a single descent. In this case, the height of fall is 4.9 m, which means that the water falls from a height of 4.9 meters before it enters the filter medium. This height is determined based on the design and operational parameters of the filter, and it plays a crucial role in determining the filtration rate and efficiency of the filter.