Question

a wrench is dropped by a worker at a construction site. four seconds later the worker hears it hit the ground below. How high is the worker above the ground? (The velocity of sound is 1100 ft/s, and the distance the wrench falls as a function of time is s=6t^2

Answer 1

so, you have (assuming the real world)

d = 16t^2, so t = √(d/16)
That's how long it takes to fall a distance d.

The sound takes another d/1100 seconds to get back. Thus, you have

√d/4 + d/1100 = 4

That's just a quadratic equation, so finding √d is easy