To calculate the velocity with which the stone hits the water surface, we need to use the formula for velocity:
v = d/t
where v is the velocity, d is the distance traveled, and t is the time taken.
In this case, we know that the stone takes 2 seconds to reach the water surface, which gives us the value of t. However, we need to determine the distance traveled by the stone before it hits the water surface.
Assuming that the well is a vertical drop, we can use the formula for the distance traveled by a falling object:
d = 1/2 * g * t^2
where g is the acceleration due to gravity, which is approximately 9.8 m/s^2 near the Earth's surface.
Plugging in the values, we get:
d = 1/2 * 9.8 m/s^2 * (2 s)^2
= 19.6 m
Therefore, the distance traveled by the stone before hitting the water surface is 19.6 meters.
Now we can use the velocity formula to calculate the velocity with which the stone hits the water surface:
v = d/t
= 19.6 m / 2 s
= 9.8 m/s
Therefore, the velocity with which the stone hits the water surface is 9.8 meters per second.