A rock is dropped from a sea cliff and hits the water 3.2s later. How high is the cliff?
t = sqrt(2y/g)
3.2 = sqrt(2y/9.81)
y = 50.23 m
How long would it take sound to travel the same distance?
t = 50.23 / 343 m/s
t = 0.15 s
How long would it take light to travel this distance?
t = 50.23 / 299 792 458 m / s
t = 1.68x10^-7 s