Answer:
S = 11.025 m
Explanation:
Given,
The time taken by the pebble to hit the water surface is, t = 1.5 s
Acceleration due to gravity, g = 9.8 m/s²
Using the II equations of motion
             S = ut + 1/2 gt²
Here u is the initial velocity of the pebble. Since it is free-fall, the initial velocity
                u = 0
Therefore, the equation becomes
              S = 1/2 gt²
Substituting the given values in the above equation
               S = 0.5 x 9.8 x 1.5²
                 = 11.025 m
Hence, the distance from the edge of the well to the water's surface is, S = 11.025 m