If a stone dropped into a well reaches the water's surface after 3.0 seconds, how far did the stone drop before hitting the water?

Explanation:

It is given that,

The stone reaches the water surface is 3 seconds. Let d is the distance covered by the by the stone before hitting the water. Initial speed of the stone, u = 0

Using second equation of motion to find the distance covered.

Here, a = g

d = 44.1 meters

So, the stone will cover a distance of 44.1 meters before hitting the water. Hence, this is the required solution.

earth's neighboring galaxy, the andromeda galaxy, is a distance of 2.54×107 light-years from earth. if the lifetime of a human is taken to be 70.0 years, a spaceship would need to achieve some minimum speed min to deliver a living human being to this galaxy.