A rock dropped from a window in a tall building hits the ground in 3 seconds. How far did the rock fall in feet?

The equation of motion 

s= ut + 1/2 at^2

can be used to solve this question. In this equation, s is the distance traveled, u is the initial velocity, t is the time taken and a is the acceleration.

Since, the rock is dropped, the initial velocity of the rock is 0 m/s. That is,

u = 0 m/s

The acceleration of the rock would be equal to the acceleration due to gravity, g. The value of g (approximately) 9.81 m/s^2 or 32.2 ft/s^2. 

And, time taken for the rock to hit the ground, t = 3 s.

Substituting the values of u, t and a in the equation, we get:

s = 0 x 3 + 1/2 x 32.2 x 3^2 = 144.9 ft.

Thus, the rock dropped from the window will travel a distance of about 144.9 ft before hitting the ground.

Hope this helps.