Physics Problem: Free Fall of Water Drops

What are the distances of the second and third drops from the roof?

Given that drops of water fall from the roof of a building 9m high at regular intervals of time, with the first drop reaching the ground at the same instant the fourth drop starts to fall.

Distances of the Second and Third Drops from the Roof:

The distance of the second drop from the roof comes out to be -10.6 meters, meaning it has already hit the ground and gone beyond. The distance of the third drop from the roof is 4.1 meters.

In this physics problem involving free fall, the distance of the second drop from the roof is calculated to be -10.6 meters, indicating that it has already reached the ground and gone beyond by 10.6 meters. On the other hand, the distance of the third drop from the roof is 4.1 meters.


This physics problem revolves around the concept of free fall in constant gravitational acceleration. When the first drop of water hits the ground, it marks the commencement of the fourth drop's fall. This implies that three intervals of time have passed since the first drop initiated its descent.


To determine the distances of the second and third drops from the roof, we utilize the equation of motion: distance = ½gt². Here, g represents the acceleration due to gravity, which is approximately 9.8 m/s². The unit of time (t) employed is the duration a drop requires to fall.


As the second drop has fallen for 2 units of time when the first drop reaches the ground, and the third drop has descended for 1 unit of time, the calculations are as follows:

For the second drop, distance = ½*9.8*(2)² = 19.6 m from the ground.

For the third drop, distance = ½*9.8*(1)² = 4.9 m from the ground.

However, considering that the total height of the building is 9m, the distances of the second and third drops from the roof are:

For the second drop, distance from the roof = 9 - 19.6 = -10.6 m.

For the third drop, distance from the roof = 9 - 4.9 = 4.1 m.

It is important to note that the negative distance of the second drop indicates that it has already arrived at the ground and proceeded beyond by 10.6 meters.

← Airy stress function in two dimensions a reflective analysis Reflecting on the size of atoms →